Thread
Mac Portable, Dead Battery, Compatible AC Adapters
The weekend is fast approaching. Hoping you can give it a change then!
ya i know, ;-)
Looks like I am going to be placing an order from digikey for some of these caps, I ran out of stock on a couple of them. Weeee......
Anyway, as a sidenote, i can discuss a little bit about the circuit design of my board. not every board is the same, some of them have integrated power supply hybrid IC, mine does not.
It has 2 DC-DC circuits onboard, both of them Linear Technologies branded parts. LT1054CS, and LT1070C
the LT1070C appears to the 5V regulator circuit to power all the logic circuits. Has a rather large inductor. It also has a wide range of input voltages, up to 60v. But when its configured for 5V out, it has a power handling capacity of 10amps in its output. Of course, thats heatsinked and everything, plus at about 60 to 80% efficiency, you would need at least 15 or 20 amps input. lol.
Anyway, since its not heatsinked, its probably setup to deliver around an amp or two on 5V. there are alot of 5V logic circuits including the drives as well, so you need something beefy to supply 5V.
On the other hand, the LT1054CS circuit has a maximum voltage input of 15V, so that pretty much limits the portables power input handling at tops 15V. since this is a switched-capacitor based circuit, I am assuming this supplies 3.3v for the logic circuits. Maybe 12v, but im not sure what part of the motherboard would need 12V except for the drives. Then again, i could have it all backwards and the LT1054 circuit supplies the 5V and the beefy 1070C circuit supplies the 12V. Not sure, will not know until i rebuild my board to get it to fire up. the caps are so bad they are leaking through the PCB Vias. But what I do know are the facts I had stated about power input handling capabilities and what circuits they are.
Ok, now for the part you might be interested in:
the DC jack appears to feed into an IRF9Z30 P type MOSFET Switch. the jack also has a sense switch when something is plugged in, will break from ground. This goes down to another linear technology part, the Sense OP-AMP. its output goes back to the 9Z30. From there it probably turns on the 9Z30 to allow current to come in.
The main power bus from the 9Z30 when switched on, goes directly into the battery via a fuse. So the circuits ARE interconnected via only a single IRF9Z30. Thats it. this 9Z30 is NOT heatsinked. So, if run entirely off the DC jack, you could in theory allow the 9Z30 to run hotter because its RDS(on) isnt very good. But really, thats it. Also it goes through a pico fuse of unknown type, so it could in theory pop the fuse, but i doubt it.
Once through the fuse, and into the 4pin battery jack, I dont know where it goes, it branches off into an internal power plane.
the DC jack/battery power bus also feeds into Q15, another IRF9Z30 that feeds voltage to both the LT1070C, and LT1054CS circuit, to supply it power. So this MOSFET serves as a power on/off switch to this regulators, this is controlled by Q204 SMD transistor.
Also, near the battery jack, with a heatsink is Q16, and L10 which form once another DC-DC converter circuit. Not sure of output voltage. Probably since it has a large heatsink, one of the voltages that requires a high load, such as the 12V for the drives. Battery output also goes to Q20, which serves to only switch on/off the LCD display.
From looking at this, it seems the DC jack keeps the system hot all the time until the charge monitor cuts off the 9Z30 so the battery will discharge to the point where the DC jack cuts in again. A form of trickle-charging.
So there you go, To enable a portable to run without the battery safely, all you need to do is short the source and drain on Q1, IRF9Z30 at the DC jack. This will interconnect the DC jack to the same bus as the battery. To feel safer, you could remove Q1 entirely and do the same. Short Source and Drain. Reason i say this, if Q1 ever shorts internally, itll short Drain and Source, AND.. Gate together which will blow the LT op-amp. and its game over.
Anyway, as a sidenote, i can discuss a little bit about the circuit design of my board. not every board is the same, some of them have integrated power supply hybrid IC, mine does not.
It has 2 DC-DC circuits onboard, both of them Linear Technologies branded parts. LT1054CS, and LT1070C
the LT1070C appears to the 5V regulator circuit to power all the logic circuits. Has a rather large inductor. It also has a wide range of input voltages, up to 60v. But when its configured for 5V out, it has a power handling capacity of 10amps in its output. Of course, thats heatsinked and everything, plus at about 60 to 80% efficiency, you would need at least 15 or 20 amps input. lol.
Anyway, since its not heatsinked, its probably setup to deliver around an amp or two on 5V. there are alot of 5V logic circuits including the drives as well, so you need something beefy to supply 5V.
On the other hand, the LT1054CS circuit has a maximum voltage input of 15V, so that pretty much limits the portables power input handling at tops 15V. since this is a switched-capacitor based circuit, I am assuming this supplies 3.3v for the logic circuits. Maybe 12v, but im not sure what part of the motherboard would need 12V except for the drives. Then again, i could have it all backwards and the LT1054 circuit supplies the 5V and the beefy 1070C circuit supplies the 12V. Not sure, will not know until i rebuild my board to get it to fire up. the caps are so bad they are leaking through the PCB Vias. But what I do know are the facts I had stated about power input handling capabilities and what circuits they are.
Ok, now for the part you might be interested in:
the DC jack appears to feed into an IRF9Z30 P type MOSFET Switch. the jack also has a sense switch when something is plugged in, will break from ground. This goes down to another linear technology part, the Sense OP-AMP. its output goes back to the 9Z30. From there it probably turns on the 9Z30 to allow current to come in.
The main power bus from the 9Z30 when switched on, goes directly into the battery via a fuse. So the circuits ARE interconnected via only a single IRF9Z30. Thats it. this 9Z30 is NOT heatsinked. So, if run entirely off the DC jack, you could in theory allow the 9Z30 to run hotter because its RDS(on) isnt very good. But really, thats it. Also it goes through a pico fuse of unknown type, so it could in theory pop the fuse, but i doubt it.
Once through the fuse, and into the 4pin battery jack, I dont know where it goes, it branches off into an internal power plane.
the DC jack/battery power bus also feeds into Q15, another IRF9Z30 that feeds voltage to both the LT1070C, and LT1054CS circuit, to supply it power. So this MOSFET serves as a power on/off switch to this regulators, this is controlled by Q204 SMD transistor.
Also, near the battery jack, with a heatsink is Q16, and L10 which form once another DC-DC converter circuit. Not sure of output voltage. Probably since it has a large heatsink, one of the voltages that requires a high load, such as the 12V for the drives. Battery output also goes to Q20, which serves to only switch on/off the LCD display.
From looking at this, it seems the DC jack keeps the system hot all the time until the charge monitor cuts off the 9Z30 so the battery will discharge to the point where the DC jack cuts in again. A form of trickle-charging.
So there you go, To enable a portable to run without the battery safely, all you need to do is short the source and drain on Q1, IRF9Z30 at the DC jack. This will interconnect the DC jack to the same bus as the battery. To feel safer, you could remove Q1 entirely and do the same. Short Source and Drain. Reason i say this, if Q1 ever shorts internally, itll short Drain and Source, AND.. Gate together which will blow the LT op-amp. and its game over.
To add, What does this all mean? Well.. A complete paradox! Something that probably started all this confusion IMHO.
Something has to turn on that IRF9Z30 before DC jack power will get into the system, maybe the PRAM or main batt does this, still needs investigated. Maybe enough charge leaks by for it to turn on by itself. However i highly doubt it. If there is no other power available ANYWHERE inside that board, the 9Z30 cannot turn on to let DC current in. So if the main batt is completely wasted, i guess that roll is taken over by the small 9V. So basically by apple putting that transistor switch on the DC jack without some sort of trickle-back feedback, you now have a chicken and the egg syndrome.
it also kind-of puts to rest about the 1.5Amp charger not running the machine by itself. Then if this is the case, if its not enough to run the system on its own, then how do we expect it to run the system AND charge the main battery when the main battery is low? because then it would pull MORE current. not less....... I guess in this case the machine has to be OFF before the batt can charge, Which like i said, Q15 and Q20 is in charge of this, it can cut off the DC-DC circuits and the LCD just from these two transistors alone. Then you have Q18 which im not sure of its function, it also, can be turned off.
But once the battery is charged, yes the system could run, BUT, if the AC adapter cannot run the board by itself, then its going to start pulling from the battery. Therefore youll notice the battery slowly start going dead while the machine is running! So if the batt stays charged while plugged in and running, then the 1.5Amp theory is out the window, as the charger CAN run the board by itself (missing batt/batt charged 100%).
There are various smaller DC circuits around the board which probably what preserve RAM when the rest of the regulators are powered off.
So crunch on this for awhile. I have never operated or owned a portable until recently, so maybe it ONLY runs on the batt and once dead it has to shut down and charge. I dunno.
Something has to turn on that IRF9Z30 before DC jack power will get into the system, maybe the PRAM or main batt does this, still needs investigated. Maybe enough charge leaks by for it to turn on by itself. However i highly doubt it. If there is no other power available ANYWHERE inside that board, the 9Z30 cannot turn on to let DC current in. So if the main batt is completely wasted, i guess that roll is taken over by the small 9V. So basically by apple putting that transistor switch on the DC jack without some sort of trickle-back feedback, you now have a chicken and the egg syndrome.
it also kind-of puts to rest about the 1.5Amp charger not running the machine by itself. Then if this is the case, if its not enough to run the system on its own, then how do we expect it to run the system AND charge the main battery when the main battery is low? because then it would pull MORE current. not less....... I guess in this case the machine has to be OFF before the batt can charge, Which like i said, Q15 and Q20 is in charge of this, it can cut off the DC-DC circuits and the LCD just from these two transistors alone. Then you have Q18 which im not sure of its function, it also, can be turned off.
But once the battery is charged, yes the system could run, BUT, if the AC adapter cannot run the board by itself, then its going to start pulling from the battery. Therefore youll notice the battery slowly start going dead while the machine is running! So if the batt stays charged while plugged in and running, then the 1.5Amp theory is out the window, as the charger CAN run the board by itself (missing batt/batt charged 100%).
There are various smaller DC circuits around the board which probably what preserve RAM when the rest of the regulators are powered off.
So crunch on this for awhile. I have never operated or owned a portable until recently, so maybe it ONLY runs on the batt and once dead it has to shut down and charge. I dunno.
techknight, you certainly are the Knight of Tech!
But in light of your technical explanation, how do you use that information to explain what Apple clearly writes here:
"It might be possible to use an AC/DC 9-volt adapter to power the system, thus eliminating the need for the lead acid battery"
Source page: http://support.apple.com/kb/TA40602?viewlocale=en_US
Or are you going under the assumption that the word "might" used on that web page is just that -- something completely untested by Apple and nothing more than a "wild guess" by them? And yet, does Apple normally post wild guesses on their website that are not based in fact at all or otherwise could pose a danger? Would the author of that Apple page not first have consulted with Apple engineers to see if the content of that page were safe to recommend?
I would appreciate hearing your thoughts on this.
Thanks.
But in light of your technical explanation, how do you use that information to explain what Apple clearly writes here:
"It might be possible to use an AC/DC 9-volt adapter to power the system, thus eliminating the need for the lead acid battery"
Source page: http://support.apple.com/kb/TA40602?viewlocale=en_US
Or are you going under the assumption that the word "might" used on that web page is just that -- something completely untested by Apple and nothing more than a "wild guess" by them? And yet, does Apple normally post wild guesses on their website that are not based in fact at all or otherwise could pose a danger? Would the author of that Apple page not first have consulted with Apple engineers to see if the content of that page were safe to recommend?
I would appreciate hearing your thoughts on this.
Thanks.
just depends on where the information had been obtained from inside apple. In theory, its possible. From an engineering standpoint, something needs to turn on that IRF9Z30 FET before DC power can come through. the 9V battery may do that.
But when I get mined restored, I am removing Q1 completely and jumpering it. i bet it runs fine.
as for running the system ENTIRELY off of the 9V battery jack, i dont think so. not only the gauge wire they use isnt thick enough, Im not sure where the 9V connects up into the circuit becuase it runs inside an inner layer of the system board. Also they quote a question someone asked, They state this "It might be possible to use an AC/DC 9-volt adapter to power the system,". I emphasize on the word MIGHT, with basically the same idea as you.
when someone says MIGHT, it basically means they have no f***in idea.
For me though, if i were to guess, the 9V probably connects into the same power bus is the rest of the circuit, its just when the main battery dies and AC power isnt connected, the DC-DC circuits shut down completely, 9V only keeps the PRAM and PSRAM up, assuming the sense and select circuit detects the presence of 9V but absense of main batt/AC.
But when I get mined restored, I am removing Q1 completely and jumpering it. i bet it runs fine.
as for running the system ENTIRELY off of the 9V battery jack, i dont think so. not only the gauge wire they use isnt thick enough, Im not sure where the 9V connects up into the circuit becuase it runs inside an inner layer of the system board. Also they quote a question someone asked, They state this "It might be possible to use an AC/DC 9-volt adapter to power the system,". I emphasize on the word MIGHT, with basically the same idea as you.
when someone says MIGHT, it basically means they have no f***in idea.
For me though, if i were to guess, the 9V probably connects into the same power bus is the rest of the circuit, its just when the main battery dies and AC power isnt connected, the DC-DC circuits shut down completely, 9V only keeps the PRAM and PSRAM up, assuming the sense and select circuit detects the presence of 9V but absense of main batt/AC.
Yes, but this is Apple we are talking about. Furthermore, they as an American company (in outrageously litigious US of A) have to take care when offering advice about anything. Hence, it seems illogical to me that they would flippantly post such information, especially without first having consulted with Apple Engineering.
My problem is that I don't have a Portable to test if connecting a 9-volt, 3-amp variable power supply to the 9v alkaline battery connector of the Portable (with all other adapters and batteries removed) would work in firing up the Portable and keeping it running. Therefore, if any of you Portable owners have such a power supply and are adventurous enough, would you be willing to perform the test?
Hi,
I have several Mac Portables.
Since it's a valuable machine I recommand to rebuild the main battery. The battery housing is very easy to open and you can either replace the old 2 volt Lead Acid Cells with Hawker "Cyclon X" 2 Volt cells ( 3x of them ) , which are 100% identical to the original one's, or use a cheap 6 volt Lead-Acid battery of 5 Amps.
As for booting with high current power adapters only: It can kill your logic board as the circuitry is not designed to work on a power adapter only. Otherwise one would assume that Apple would have included a more powerfull PSU. The Powerbook 100 and all other powerbooks I have ( 100, Duo and 500 series ) perfectly work without the battery. The Mac Portable M5120 can work on even on the original 1.5 Amps PSU, if you disconnect the Connor Hard drive as this drive asks more than 2 Amps just to spinup.
The logic boards of the Mac portables regrattably also suffer badly of leaking capacitors: all the SMD capacitors are shot ( ESR > 20 Ohm ), also in most cases the axial and radial one's too. If you want to keep your Mac portable running in the long term: capacitor replacement is a must as soon as possible.
It will fix many issues with charging, no or whining sound, rolling barrs when adjusting screen contrast, instability, if the electronical components haven't suffered too much already...
After replacing the capacitors, you can also measure that the machine draws less power to start and also in standby/sleep.
As you will probably already know, the Mac Portables are always in Sleep mode even if you choose "Shutdown" in Mac OS: it makes no difference towards power consumption between Sleep and Shutdown. Even a fully recapped Mac portable drains a fully charged battery in about 7 days.
Good Luck,
Nico
I have several Mac Portables.
Since it's a valuable machine I recommand to rebuild the main battery. The battery housing is very easy to open and you can either replace the old 2 volt Lead Acid Cells with Hawker "Cyclon X" 2 Volt cells ( 3x of them ) , which are 100% identical to the original one's, or use a cheap 6 volt Lead-Acid battery of 5 Amps.
As for booting with high current power adapters only: It can kill your logic board as the circuitry is not designed to work on a power adapter only. Otherwise one would assume that Apple would have included a more powerfull PSU. The Powerbook 100 and all other powerbooks I have ( 100, Duo and 500 series ) perfectly work without the battery. The Mac Portable M5120 can work on even on the original 1.5 Amps PSU, if you disconnect the Connor Hard drive as this drive asks more than 2 Amps just to spinup.
The logic boards of the Mac portables regrattably also suffer badly of leaking capacitors: all the SMD capacitors are shot ( ESR > 20 Ohm ), also in most cases the axial and radial one's too. If you want to keep your Mac portable running in the long term: capacitor replacement is a must as soon as possible.
It will fix many issues with charging, no or whining sound, rolling barrs when adjusting screen contrast, instability, if the electronical components haven't suffered too much already...
After replacing the capacitors, you can also measure that the machine draws less power to start and also in standby/sleep.
As you will probably already know, the Mac Portables are always in Sleep mode even if you choose "Shutdown" in Mac OS: it makes no difference towards power consumption between Sleep and Shutdown. Even a fully recapped Mac portable drains a fully charged battery in about 7 days.
Good Luck,
Nico
Not going to "kill" anything.
The AC adapter and battery end up on the same exact power bus. only a MOSFET in between, and a picofuse. the reason the battery has to be in place with juice is because something has to turn on this mosfet to allow DC current to flow into the circuit from the adapter.
The AC adapter and battery end up on the same exact power bus. only a MOSFET in between, and a picofuse. the reason the battery has to be in place with juice is because something has to turn on this mosfet to allow DC current to flow into the circuit from the adapter.
In consideration of the last two posts, I'd like to repeat what I said before...
:approve: My two cents, having read portions of this board are the following - P.S I own 18 Mac Portables, and have been studying them for a long time.
1. The whole thing about removing the batteries and putting a 9v feed in on the PRAM battery thing is just stupid, the whole idea of the battery cradle is to temporarily give the logic a bit of juice while swapping in and out the main battery to keep date/time. Amazingly, the machine will actually turn on with a brand new 9v battery if the hard disk is disconnected and you don't try and boot from a floppy. Of course, this will only work if the battery cover is off, and for a few minutes before killing the battery.
2. With the main battery removed, and the battery cover on, any PSU of 7.5v and 2a or over should turn over the machine, however I know some of my units will only turn over with the 3A 7.5v PSU's... Not sure why, as some get very edgy with the 3A PSU.
3. I always personally stick to the 7.5v 2A adaptors for safety, but always revert to the 1.5a cream adaptor when I have a good SLA battery in, the charge circuit seems to suck more amperage, and charge faster when available and in my experience shortened the overall battery life.
4. The Power controller on the Mac Portable is very funny and moving between power sources can scramble the boards a bit. Pressing both the reset and interrupt together a few times usually fixes them up, but I have had times where i've had to leave boards for a few days without power for them to be happy again.
5. If you are not going to rebuild the main 6v 5.0ah SLA, my experience is - best to remove both batteries and put back on the battery cover before connecting power supplies.
The Mac Portable is a very interesting machine, they really are one of my favourite mac's. However they are also the most unstable mac's without the SMD caps being replaced and a good PSU.
I only ask everyone, test your Apple PSU's before plugging them in, as many of those Cream and Grey PSU's are going supernova now, and dishing out either way too little, or way too much power.
Hope I've offered something of use to someone here.
1. The whole thing about removing the batteries and putting a 9v feed in on the PRAM battery thing is just stupid, the whole idea of the battery cradle is to temporarily give the logic a bit of juice while swapping in and out the main battery to keep date/time. Amazingly, the machine will actually turn on with a brand new 9v battery if the hard disk is disconnected and you don't try and boot from a floppy. Of course, this will only work if the battery cover is off, and for a few minutes before killing the battery.
2. With the main battery removed, and the battery cover on, any PSU of 7.5v and 2a or over should turn over the machine, however I know some of my units will only turn over with the 3A 7.5v PSU's... Not sure why, as some get very edgy with the 3A PSU.
3. I always personally stick to the 7.5v 2A adaptors for safety, but always revert to the 1.5a cream adaptor when I have a good SLA battery in, the charge circuit seems to suck more amperage, and charge faster when available and in my experience shortened the overall battery life.
4. The Power controller on the Mac Portable is very funny and moving between power sources can scramble the boards a bit. Pressing both the reset and interrupt together a few times usually fixes them up, but I have had times where i've had to leave boards for a few days without power for them to be happy again.
5. If you are not going to rebuild the main 6v 5.0ah SLA, my experience is - best to remove both batteries and put back on the battery cover before connecting power supplies.
The Mac Portable is a very interesting machine, they really are one of my favourite mac's. However they are also the most unstable mac's without the SMD caps being replaced and a good PSU.
I only ask everyone, test your Apple PSU's before plugging them in, as many of those Cream and Grey PSU's are going supernova now, and dishing out either way too little, or way too much power.
Hope I've offered something of use to someone here.
digitalrampage, thank you for your feedback. I am especially grateful of your words because who among us has so many Mac Portables? My goodness!
But my question was not directly answered by what you wrote. And perhaps that is because you lack a "variable" power supply. The situation is that an associate of mine who owns a Mac Portable cannot get it to work. He has adapters but none of them will boot the Portable and one of them, which should have worked, tested dead. So he lacks the required "working" adapters to test what you wrote. However, he has a "variable voltage" power supply. But before I instruct him to go ahead and connect that PSU to his Portable to test and see what happens, I first want to know who among us has done this. Yes, yes, I know many of you read this have tested AC ADAPTERS. But that is not the same as using a true variable-voltage power supply. I am not sure if my associate has a supply which also allows him to limit the Current too. He only told me he can vary the Voltage.
So who among us has connected a variable voltage power supply (NOT an AC Adpater) and successfully booted a Portable (internal hard drive included) and used that long enough to determine that such a power supply (at a particular set voltage and current) will NOT harm the Portable? That is what I wish to know. Surely there is at least one Mac Portable owner out there reading this who has tested this at least once.
I look forward to your replies.
But my question was not directly answered by what you wrote. And perhaps that is because you lack a "variable" power supply. The situation is that an associate of mine who owns a Mac Portable cannot get it to work. He has adapters but none of them will boot the Portable and one of them, which should have worked, tested dead. So he lacks the required "working" adapters to test what you wrote. However, he has a "variable voltage" power supply. But before I instruct him to go ahead and connect that PSU to his Portable to test and see what happens, I first want to know who among us has done this. Yes, yes, I know many of you read this have tested AC ADAPTERS. But that is not the same as using a true variable-voltage power supply. I am not sure if my associate has a supply which also allows him to limit the Current too. He only told me he can vary the Voltage.
So who among us has connected a variable voltage power supply (NOT an AC Adpater) and successfully booted a Portable (internal hard drive included) and used that long enough to determine that such a power supply (at a particular set voltage and current) will NOT harm the Portable? That is what I wish to know. Surely there is at least one Mac Portable owner out there reading this who has tested this at least once.
I look forward to your replies.
What do I risk in hooking up a variable voltage supply to my Portable that is running in good condition? My brother has all sorts of Tektronix equipment including a variable voltage supply module but I'd be loathe to power my Portable from it if there was a chance of harming it.
Indeed. But techknight's previous posts indicates his confidence that it wouldn't be harmed. Unfortunately, he appears to lack the Portable necessary to test the Theory with the Experimental.
you want to keep the voltage CONSTANT. dont variate the voltage. The DC-DC converters in theory should handle that, but itll put more stress on them
ok. Question: Can you run a portable solely on the 9V connector.
Answer: YES. You can. I tried it, it works. Idles at 1.80amps, takes about 2.2 amps surge to spin up the drive. There is a catch. You must have the battery cover removed. Why? the 9v isnt connected to the circuit at all until the saftey interlock is disengaged. The interlock switches out the 6V battery and switches in the 9V battery when the cover is slid off and removed.
Is it advisable? no. Why? it runs the switching regulators harder/hotter. Heat shortens the lifetime of components in the long run.
I cant get my backlit portable to solely run off the AC adapter input, there is too much voltage drop on the 5V switching regulator when loaded, so I have to mod the circuitry so that I can
Answer: YES. You can. I tried it, it works. Idles at 1.80amps, takes about 2.2 amps surge to spin up the drive. There is a catch. You must have the battery cover removed. Why? the 9v isnt connected to the circuit at all until the saftey interlock is disengaged. The interlock switches out the 6V battery and switches in the 9V battery when the cover is slid off and removed.
Is it advisable? no. Why? it runs the switching regulators harder/hotter. Heat shortens the lifetime of components in the long run.
I cant get my backlit portable to solely run off the AC adapter input, there is too much voltage drop on the 5V switching regulator when loaded, so I have to mod the circuitry so that I can
It seems like there has to be someoneout there that either rebuilds these batteries or knows how. I'd love to see my portable boot up. I don't even know if it works.
What are your thoughts on the following, where the seller (DWBOWERS) claims, "This Portable boots and runs fine without the battery using the included PowerBook power supply"?
http://www.ebay.com/itm/Macintosh-Portable-Vintage-Computer-Used-by-NASA-6MB-RAM-Excellent-condition-/140807426423?pt=US_Vintage_Computers_Mainframes&hash=item20c8c6d177#ht_500wt_922
He also has a backlit one too, in which listing he claimed the same thing about the PowerBook adapter until I contacted him about reliability, directing him to this thread. I wrote him 3 times via EBAY, but he merely changed his listing without replying back to me at all. I find that odd in light of his excellent reputation score and wonderful photos. And it brings up the same issue we've pondered in this thread — it is really safe to use a PowerBook adapter to owner a Portable in the long term? We really didn't come to any definitive conclusion in this thread, other than to deed TechKnight's warning about the potential for burned down resistors, as well as less than reliable booting (unless you've replaced the hard drive with a flash drive).
Anyway, here's the backlit one:
http://www.ebay.com/itm/Macintosh-Portable-Backlit-Model-M5126-with-Battery-Power-Adapter-and-Case-/140807393958?pt=US_Vintage_Computers_Mainframes&hash=item20c8c652a6
http://www.ebay.com/itm/Macintosh-Portable-Vintage-Computer-Used-by-NASA-6MB-RAM-Excellent-condition-/140807426423?pt=US_Vintage_Computers_Mainframes&hash=item20c8c6d177#ht_500wt_922
He also has a backlit one too, in which listing he claimed the same thing about the PowerBook adapter until I contacted him about reliability, directing him to this thread. I wrote him 3 times via EBAY, but he merely changed his listing without replying back to me at all. I find that odd in light of his excellent reputation score and wonderful photos. And it brings up the same issue we've pondered in this thread — it is really safe to use a PowerBook adapter to owner a Portable in the long term? We really didn't come to any definitive conclusion in this thread, other than to deed TechKnight's warning about the potential for burned down resistors, as well as less than reliable booting (unless you've replaced the hard drive with a flash drive).
Anyway, here's the backlit one:
http://www.ebay.com/itm/Macintosh-Portable-Backlit-Model-M5126-with-Battery-Power-Adapter-and-Case-/140807393958?pt=US_Vintage_Computers_Mainframes&hash=item20c8c652a6
Just rebuild the battery and you take no risk at all. It's the easiest battery I know from a laptop to rebuild.
In the end, why would you take any risk if you can perfectly buy the original cells brand new from the Manufacturer ?
You need 3x of these:
http://cellpacksolutions.com/Search_Data_Sheet.asp?ID=0800-0004
For only 22.5£ or about 35USD you can have recell your original battery and it will be good for at least 5 years ( if you don't let it drain completely ).
I have recelled the battery of all my Mac Portables: the oldest is now about 5 years old and frequently charged about 4x times a week nevertheless with a full charge and LCD & HDD always On + rest mode disable it still lasts over 3 hours.
Another argument is that Mac Portables with the original white power adapter and a rebuild battery a worth more than one with a dead battery and a PB100 adapter, not only from a collector's perspective but also on Ebay for example.
In the end, why would you take any risk if you can perfectly buy the original cells brand new from the Manufacturer ?
You need 3x of these:
http://cellpacksolutions.com/Search_Data_Sheet.asp?ID=0800-0004
For only 22.5£ or about 35USD you can have recell your original battery and it will be good for at least 5 years ( if you don't let it drain completely ).
I have recelled the battery of all my Mac Portables: the oldest is now about 5 years old and frequently charged about 4x times a week nevertheless with a full charge and LCD & HDD always On + rest mode disable it still lasts over 3 hours.
Another argument is that Mac Portables with the original white power adapter and a rebuild battery a worth more than one with a dead battery and a PB100 adapter, not only from a collector's perspective but also on Ebay for example.
Why? Because even a newly rebuilt battery will die in time. And because I really wouldn't need a battery since the Portable is not so "portable." And because even a newly rebuilt battery will run down over time, prompting me to either keep it perpetually connected (which I do not want to do), or connect, disconnect, and connect it frequently. Otherwise, the battery voltage will get too low, and I've read that such is a big no-no with Portable batteries.
Hence, it makes much more sense, and it is much more convenient, if we could "safely" use an AC adapter to power the Portable, without the need for any batteries inside it.
Hence, it makes much more sense, and it is much more convenient, if we could "safely" use an AC adapter to power the Portable, without the need for any batteries inside it.
If you want to use your Mac Portable on a PSU only: that's fine.
I prefer to keep my collection as original as possible, so that's with a working battery.
Let's be realistic: what's 44USD for a working battery ?
You pay 5x times that much for a replacement Lithium-ion battery for a new laptop now and it's dead in 2 or 3 years.
As for the draining of the Mac Portable's battery: yes it drains his battery, however with the logic board recapped it takes a fully charged battery 2,5 weeks to drain so if you charge it regularly the draining is not an issue at all.
I feel very comfordable with a Mac Portable lasting 3 hours on battery power, with all power savings disabled. Set them on and it's even longer.
There aren't many new laptops around that will beat this time, only a few with very expensive one's with SSD drives...
I prefer to keep my collection as original as possible, so that's with a working battery.
Let's be realistic: what's 44USD for a working battery ?
You pay 5x times that much for a replacement Lithium-ion battery for a new laptop now and it's dead in 2 or 3 years.
As for the draining of the Mac Portable's battery: yes it drains his battery, however with the logic board recapped it takes a fully charged battery 2,5 weeks to drain so if you charge it regularly the draining is not an issue at all.
I feel very comfordable with a Mac Portable lasting 3 hours on battery power, with all power savings disabled. Set them on and it's even longer.
There aren't many new laptops around that will beat this time, only a few with very expensive one's with SSD drives...
Since the Portable would not be my primary computer, nor the only vintage Mac in my collection, regularly charging of the battery once every 2 or 3 weeks would be a burden indeed. That's especially true if you've got a family, young kids, a busy job, etc., which may lead to your forgetting to charge the battery at times. That may not be true for everyone, especially if you use the Portable often. But realistically, who among us is so willing to faithfully charge the battery every 2 to 3 weeks? And who among us could keep that up for 2 to 3 years (whatever the life is of the replacement battery)? And who really wants to replace a $45 battery every 2-3 years if the Portable isn't used often? Perhaps there are a few, but I am not among them.
So I think you can see my point. Powering it off a dedicated PSU (benchtop power supply) really isn't desirable either as most people don't own one, and they are rather big and bulky. When I speak of an "AC Adapter" I am referring to a compact PowerBook AC Adapter, which the EBAY seller is referring to, and which we have discussed earlier in this thread. But as discussed previously, TechKnight believes that long term use of such could fry some onboard resistors. He simply doesn't know which resistors. I suppose if we did know which resistors, we could theoretically replace them with higher wattage versions and be done with the worry altogether. If so, that might be the best solution all around.
So I think you can see my point. Powering it off a dedicated PSU (benchtop power supply) really isn't desirable either as most people don't own one, and they are rather big and bulky. When I speak of an "AC Adapter" I am referring to a compact PowerBook AC Adapter, which the EBAY seller is referring to, and which we have discussed earlier in this thread. But as discussed previously, TechKnight believes that long term use of such could fry some onboard resistors. He simply doesn't know which resistors. I suppose if we did know which resistors, we could theoretically replace them with higher wattage versions and be done with the worry altogether. If so, that might be the best solution all around.
Coming in VERRRRY late to the discussion, I would like to add that using some power adapters with excessively high current ratings can damage equipment. Say that you pick up a really cool looking, medieval 5V, 10A power adapter and hook it up to a couple of 7400 series chips for a school project. And they blow right up and smoke and bubble. WHY?? It was the right voltage and you only needed 1 mA! It was not actually the right voltage when you ran it with such little current.
Unless a power adapter contains a regulator to overcome it, it has internal resistance that directly affects the output voltage over the entire range of current, starting at zero. When this 5V, 10A adapter was designed, it may have initially had an open circuit output voltage of 5V, but when test technician intern ID X hooked up his awesome heatsinked potentiometer from high school to load it down, something very bad happened.
He dropped the resistance lower and lower while watching the current climb, and while one might expect this resistance to be 0.5Ω after visiting Ohm's law (5V ÷ 10A = 0.5Ω), he actually had to turn the resistance all the way down to 0.27041Ω before he reached 10 Amps. Then he tested the output voltage under this load and it was WRONG - 2.29587V. Well he can fix that.
So, eager to get this thing working and impress the other guys in the only way he knows how - sheer SPEED, the guy cracked open the transformer and began adding extra output windings to the transformer. Current and voltage went up a little with each extra winding, so he had to turn up his pot a little each time too. Finally, after more than doubling the magnet wire that was there originally, he was satisfied when his readings were 5V, 10A. So was his boss - it does exactly what the spec says - 5V at 10A. TEST PASS --> TIMELINE OBJECTIVE COMPLETE AHEAD OF SCHEDULE --> SHIP IT --> PROMOTE INTERN X TO COFFEE MACHINE SUPERVISOR --> HAVE A REFRESHING CUP OF COFFEE. (Kidding in Dilbert fashion of course.
)
Going back and testing the power adapter for open circuit voltage after this modification, it is now 10.889V because of 0.22959Ω internal resistance! Test the open circuit voltage of handful of your power adapters to see how true this story actually is.
Seriously, though, companies are VERY likely to be aware of this as they select/design power adapters, and they choose the most cost-effective one that works fine specifically with the device they bundle it with. When we try to use a high current rated adapter with a low current device, even if it's the same rated voltage, that's where we could run into problems if we don't consider voltage under different loads. I don't know if this applies to the PowerBook vs Portable power adapters damaging the PowerBook 100 but it could be tested.
Unless a power adapter contains a regulator to overcome it, it has internal resistance that directly affects the output voltage over the entire range of current, starting at zero. When this 5V, 10A adapter was designed, it may have initially had an open circuit output voltage of 5V, but when test technician intern ID X hooked up his awesome heatsinked potentiometer from high school to load it down, something very bad happened.
He dropped the resistance lower and lower while watching the current climb, and while one might expect this resistance to be 0.5Ω after visiting Ohm's law (5V ÷ 10A = 0.5Ω), he actually had to turn the resistance all the way down to 0.27041Ω before he reached 10 Amps. Then he tested the output voltage under this load and it was WRONG - 2.29587V. Well he can fix that.
So, eager to get this thing working and impress the other guys in the only way he knows how - sheer SPEED, the guy cracked open the transformer and began adding extra output windings to the transformer. Current and voltage went up a little with each extra winding, so he had to turn up his pot a little each time too. Finally, after more than doubling the magnet wire that was there originally, he was satisfied when his readings were 5V, 10A. So was his boss - it does exactly what the spec says - 5V at 10A. TEST PASS --> TIMELINE OBJECTIVE COMPLETE AHEAD OF SCHEDULE --> SHIP IT --> PROMOTE INTERN X TO COFFEE MACHINE SUPERVISOR --> HAVE A REFRESHING CUP OF COFFEE. (Kidding in Dilbert fashion of course.
)Going back and testing the power adapter for open circuit voltage after this modification, it is now 10.889V because of 0.22959Ω internal resistance! Test the open circuit voltage of handful of your power adapters to see how true this story actually is.
Seriously, though, companies are VERY likely to be aware of this as they select/design power adapters, and they choose the most cost-effective one that works fine specifically with the device they bundle it with. When we try to use a high current rated adapter with a low current device, even if it's the same rated voltage, that's where we could run into problems if we don't consider voltage under different loads. I don't know if this applies to the PowerBook vs Portable power adapters damaging the PowerBook 100 but it could be tested.
Which means its not 5V. lol. any power supply that is not regulated/loaded properly will produce voltages way different than what is written on the face.
If you have a TRUE 5V output power supply (regulated, etc..) then you cant damage anything. So 5V damaging a circuit that uses 5V is a myth unless the power supply is producing a voltage other than 5V. Or there is a problem in the circuit that causes excessive current draw, then you get a cascading failure, etc.. But then that wasnt the power supplies fault.
so if i had a 5V 200amp power supply hooked to a couple of 74XX chips, they arnt gonna blow. IF 5V = 5V. Just because a power supply is rated for excessive current, doesnt automatically assume it can damage anything.
Given proper regulation/load its fine..
But what you did say definitely a trap for young players that dont know about regulation. thats for sure. What you say is true if the 5V =/= 5V but then technically it isnt 5V is it... Only under proper regulation/load.
So, the way it should have been worded is: Using an Unregulated 5V power supply with excessive current CAN/WILL damage equipment.
Anyway, I know what you mean though, hence why you mentioned "some" power supplies. }
BUT MA, BLOWIN STUFF UP IS FUUUUUNNNN!!!!!! For example, i plugged the transformer connector in backwards while working on a Mackie 1202 Mixer that someone spilled coffee in. WHOOOPS. some caps went kerplow...
With all that aside, I dont know if the PB1XX adapters are regulated or not. if its SMPS, its fine. Anyway, I do know that some car audio equipment, they do a 30% overwind on the secondary windings of the switching transformer that feed the output rails. Running at full swing, loaded or not would blow every cap in the filter section, they arnt rated for the excess voltage. But luckily its a regulated power supply. So it keeps itself in tight feedback for output voltages. the overwind is there for peak current demand when the output section calls for it.
Not trying to start an argument, what you say IS correct in certain conditions, just bustin ya chops.
TechKnight, I often see EBAY Sellers of Mac Protables claim that they can operate the Portable perfectly, even without the main battery, by using a PowerBook 100 AC adapter. (We discussed a couple model numbers of these supposedly compatible adapters earlier in this thread.) The question therefore becomes, "are these PB adapters 'regulated'?" And if we would say that they are "regulated," are they regulated enough for a Mac Portable's electrical "load"? Evidence presented earlier in this thread seems to indicate an answer of "no" to that.
Now if someone here would kindly ship me a working Portable, and several AC adapters, with the understanding this is a scientific experiment that may damage something, we could perhaps find out once and for all, putting this 20+ year old question to rest.
Now if someone here would kindly ship me a working Portable, and several AC adapters, with the understanding this is a scientific experiment that may damage something, we could perhaps find out once and for all, putting this 20+ year old question to rest.
You make it sound like I was wrong when I clearly was not! How dare you!! :O -> > 
->
-> :scrambled:
hahaha :lol:
I have actually made that mistake once with some 7400 chips. I blindly chopped off a 4.5V adapter and wired it in, as the range is 4.5-5.5 for the ones I had. I blew 'em (no smoke though) and when I tested the voltage it was up somewhere around 8V open circuit. DANG
That was nothing compared to when I blew an I/O pin on my awesome HC12 demo board. That was very tragic.
If there actually are people out there trying to learn from what I said here, technight has a valid point -- it isn't exactly clear what I was saying. In theory, if you have a 5V adapter and the current rating is high enough, or higher, or MUCH HIGHER, that will work perfectly fine.
This is usually true in the real world because of voltage regulators, but sometimes regulators aren't used so the rated voltage of those power adapters only comes out correct at the rated current. You should either pick an adapter that matches both the voltage and current, or you should test the adapter with a voltmeter. If the voltage is correct under no load (just your voltmeter attached), then you know that it is regulated and it will be fine under smaller-than-rated current loads.
->
hahaha :lol:
I have actually made that mistake once with some 7400 chips. I blindly chopped off a 4.5V adapter and wired it in, as the range is 4.5-5.5 for the ones I had. I blew 'em (no smoke though) and when I tested the voltage it was up somewhere around 8V open circuit. DANG
That was nothing compared to when I blew an I/O pin on my awesome HC12 demo board. That was very tragic.
If there actually are people out there trying to learn from what I said here, technight has a valid point -- it isn't exactly clear what I was saying. In theory, if you have a 5V adapter and the current rating is high enough, or higher, or MUCH HIGHER, that will work perfectly fine.
This is usually true in the real world because of voltage regulators, but sometimes regulators aren't used so the rated voltage of those power adapters only comes out correct at the rated current. You should either pick an adapter that matches both the voltage and current, or you should test the adapter with a voltmeter. If the voltage is correct under no load (just your voltmeter attached), then you know that it is regulated and it will be fine under smaller-than-rated current loads.
hahahahahahahaha. It was all fun. hehe. When it comes to blowing up stuff, I think i am the master of it. lol. But thats how you learn. I once blew out 30 op-amps in a Samson powered mixer once years ago because of a polarity issue on the +/-15v rails. I stuck a 7815 in place of the 7915 by accident. Whoops.You make it sound like I was wrong when I clearly was not! How dare you!! :O -> >-> :scrambled:
hahaha :lol:
I have actually made that mistake once with some 7400 chips. I blindly chopped off a 4.5V adapter and wired it in, as the range is 4.5-5.5 for the ones I had. I blew 'em (no smoke though) and when I tested the voltage it was up somewhere around 8V open circuit. DANG
That was nothing compared to when I blew an I/O pin on my awesome HC12 demo board. That was very tragic.
If there actually are people out there trying to learn from what I said here, technight has a valid point -- it isn't exactly clear what I was saying. In theory, if you have a 5V adapter and the current rating is high enough, or higher, or MUCH HIGHER, that will work perfectly fine.
This is usually true in the real world because of voltage regulators, but sometimes regulators aren't used so the rated voltage of those power adapters only comes out correct at the rated current. You should either pick an adapter that matches both the voltage and current, or you should test the adapter with a voltmeter. If the voltage is correct under no load (just your voltmeter attached), then you know that it is regulated and it will be fine under smaller-than-rated current loads.
JDW: I think they are regulated, SMPS based supplies. I cant verify for sure as I dont have a PB100 adapter. only one that came with my PB145. I forget what it was rated for. But its rock solid no load at 7.5V so that means its regulated/SMPS based.
i have an iHome 7.5V ipod dock adapter too, its SMPS based and rated for 2A. Same deal with my portable. But if i hook a 9V adapter up to the 9V battery terminals it works fine. But it draws close to 2A though. If i hook in the 7.5V adapter I have through the battery connection, it wont hold. exceeds the 2A limit as soon as the backlight kicks on, the machine poof shuts off.
Oh P.S. I just blew an 8051 based Micro today lol. I had a keypad apart for screwing around with, the UART wires were black and red, 12V power were white and green. at least now i know. lol. I thought black and red was power, hooked up 12V and blew a hole streight in a 1995 date code 8051 micro. whoops.
TechKnight, if a truly regulated PSU is all that is needed to guarantee a Portable won't fry any circuitry over time (with or without the stock batteries attached), why not just buy a suitable PSU from JAMECO or DigiKey? One could just hack off the connector of a stock Mac Portable PSU and wire it to the regulated PSU, right? Wouldn't that be the ideal solution here?
Oh i have multiple ways to do it. I just need to pick the best one that works for me. I just need to take it to my shop one day and put it on the bench power supply and figure out the EXACT current draw at different voltage points.
has anyone done any more work on these Back-Lit Models?
for instance what is: and kindly what are the proper values?
VR1
Q1
Q15
Q16
Q20
IS U5L Voltage Regulator Replaceable?
U2L - Voltage Ref?
What are common issues with these?
For instance, what part would allow the hard drive to spin up solely from battery? Q16?
I'v got 2 back-lit boards here that are both acting funny when (only) running off a good SLA battery.
When plugged in both boards work flawlessly.
Please lets expand this thread with good complete info, I am sure there are some back-lit owners that could find this information very useful, looks like technight has a good start.
I can hodge podge something together, so i can get my multimeter on some of these parts to see what the values are, my only issue is, I do not have a properly working back-lit portable board for a base-line.
for instance what is: and kindly what are the proper values?
VR1
Q1
Q15
Q16
Q20
IS U5L Voltage Regulator Replaceable?
U2L - Voltage Ref?
What are common issues with these?
For instance, what part would allow the hard drive to spin up solely from battery? Q16?
I'v got 2 back-lit boards here that are both acting funny when (only) running off a good SLA battery.
When plugged in both boards work flawlessly.
Please lets expand this thread with good complete info, I am sure there are some back-lit owners that could find this information very useful, looks like technight has a good start.
I can hodge podge something together, so i can get my multimeter on some of these parts to see what the values are, my only issue is, I do not have a properly working back-lit portable board for a base-line.