Thread
Compact Mac CRT compatibility
Hello:
This is my first post on the 68k forum. I own three compact Macs (a 1986 512ke, which was upgraded to a 1987 Plus, a 1988 Plus, and a 1988 Mac SE (SuperDrive Model)). The 512ke works perfectly, after several of the analog board capacitors were replaced by a TV technician. The SE, which has been in the family for over 17 years, works as well, however the CRT, after many years of heavy operation, has severe screen-burn (I can post a picture as soon as I receive a reply). The 88 Plus has a faulty analog board (wavy-line syndrome on the CRT). I can get the board repaired for just under $100.00, however I would prefer to put the money towards an SE/30, or a Portable (if I can find one).
To make a long story short, I brought in my SE & Plus to the same TV technician who repaired the 512ke. The concept was to exchange the CRT from the Plus with the CRT in the SE (which has the screen-burn). The following morning, I received a phone call from the technician, who stated that the Plus display was incompatible (the voltage on the Plus was rated at 30, whereas the voltage on the SE was 400).
One would figure that both CRTs would be compatible, since they were both made by the same manufacturer (Clinton), and in the same year (1988). I have already posted a want ad on Kijiji for a donor SE, but so far no success.
Any suggestions as to why these CRTs are incompatible? I know for a fact that the Classic & Classic II monitors are incompatible with the earlier compacts (128k-SE/30).
Naturally, any help would be greatly appreciated. Cheers.
This is my first post on the 68k forum. I own three compact Macs (a 1986 512ke, which was upgraded to a 1987 Plus, a 1988 Plus, and a 1988 Mac SE (SuperDrive Model)). The 512ke works perfectly, after several of the analog board capacitors were replaced by a TV technician. The SE, which has been in the family for over 17 years, works as well, however the CRT, after many years of heavy operation, has severe screen-burn (I can post a picture as soon as I receive a reply). The 88 Plus has a faulty analog board (wavy-line syndrome on the CRT). I can get the board repaired for just under $100.00, however I would prefer to put the money towards an SE/30, or a Portable (if I can find one).
To make a long story short, I brought in my SE & Plus to the same TV technician who repaired the 512ke. The concept was to exchange the CRT from the Plus with the CRT in the SE (which has the screen-burn). The following morning, I received a phone call from the technician, who stated that the Plus display was incompatible (the voltage on the Plus was rated at 30, whereas the voltage on the SE was 400).
One would figure that both CRTs would be compatible, since they were both made by the same manufacturer (Clinton), and in the same year (1988). I have already posted a want ad on Kijiji for a donor SE, but so far no success.
Any suggestions as to why these CRTs are incompatible? I know for a fact that the Classic & Classic II monitors are incompatible with the earlier compacts (128k-SE/30).
Naturally, any help would be greatly appreciated. Cheers.
Hello LC Guy:
Thanks for the response.
I looked at Scott's thread just before I joined the 68k forum. In theory, these monitors should be compatible, however, the technician I spoke to said that they are not due to a difference in voltage rating (the SE CRT is higher than the Plus CRT). In order for both to be interchangeable, the voltages must be exactly the same, in order not to overload the analog board/power supply.
Naturally, I do not want to cause any damage to the SE (I have never had any problems with it; it's a very reliable computer), and I trust the expertise of the technician I am dealing with (he has been servicing TVs for over 40 years).
The only thing I can think of is that the analog board in my SE is not a stock SE board, but rather a Classic, or Classic II board (the SE was purchased used in March 1992). Either way, if I do not have any success with the forums, I will just have to wait for a donor SE.
Thanks for the response.
I looked at Scott's thread just before I joined the 68k forum. In theory, these monitors should be compatible, however, the technician I spoke to said that they are not due to a difference in voltage rating (the SE CRT is higher than the Plus CRT). In order for both to be interchangeable, the voltages must be exactly the same, in order not to overload the analog board/power supply.
Naturally, I do not want to cause any damage to the SE (I have never had any problems with it; it's a very reliable computer), and I trust the expertise of the technician I am dealing with (he has been servicing TVs for over 40 years).
The only thing I can think of is that the analog board in my SE is not a stock SE board, but rather a Classic, or Classic II board (the SE was purchased used in March 1992). Either way, if I do not have any success with the forums, I will just have to wait for a donor SE.
I doubt its a Classic/Classic II board - first things first, the Classic/Classic II board won't fit in a SE case without modifications, you would also need to modify the connector going to the logic board, in addition the Classic/Classic II board lacks a brightness control, which the SE board has. If you still think you have a Classic/Classic II board, there's an easy way to find out - open it up and have a look...if its an SE board, the power supply will be metal box separate to the analog board, whereas the Classic/Classic II analog board has the power supply electronics built into the analog board.
I'm surprised that the voltages would be that different - I thought they'd all be about the same throughout all the compact Macs.
I'm surprised that the voltages would be that different - I thought they'd all be about the same throughout all the compact Macs.
Hello LC Guy:
Well, the SE I own has a brightness control knob, so the theory that I may have a Classic board seems to be virtually impossible.
By any chance, were there any Revision B analog boards for the SE series (not including the SE/30; I doubt the analog board I have could be from an SE/30)? The SE I have is somewhat unique, as it is labeled "SuperDrive", as opposed to "FDHD," and predates 1989 (the unit was built sometime in 1988, as the copyright date on the back states 1988). I would have to go online to decode the serial number to find out when exactly it was built, although I doubt it may solve this incompatibility issue.
I know for a fact that the 88 Plus was built in Singapore, and the 88 SE (with the screen-burn) was built in Fremont, USA. Would this be of any significance?
Well, the SE I own has a brightness control knob, so the theory that I may have a Classic board seems to be virtually impossible.
By any chance, were there any Revision B analog boards for the SE series (not including the SE/30; I doubt the analog board I have could be from an SE/30)? The SE I have is somewhat unique, as it is labeled "SuperDrive", as opposed to "FDHD," and predates 1989 (the unit was built sometime in 1988, as the copyright date on the back states 1988). I would have to go online to decode the serial number to find out when exactly it was built, although I doubt it may solve this incompatibility issue.
I know for a fact that the 88 Plus was built in Singapore, and the 88 SE (with the screen-burn) was built in Fremont, USA. Would this be of any significance?
The term SuperDrive came after the term FDHD. So what you have is a later model FDHD. The SE FDHD did not appear until late 1989, after the SE/30, and sold for a year, until it was replaced by the Classic. Yours is likely a 1990 model.
The Power Supply for the SE/30 & SE/FDHD/SuperDrive were identical. The copyright date of the power supply is irrelevant. All it indicates is that it was updated in 1988 (from the original 1987 design), and not updated again by the time it was installed in your SE.
The Power Supply for the SE/30 & SE/FDHD/SuperDrive were identical. The copyright date of the power supply is irrelevant. All it indicates is that it was updated in 1988 (from the original 1987 design), and not updated again by the time it was installed in your SE.
Your technician is deeply confused -- so much so that it brings into question his abilities. It's obvious that he does not have the slightest understanding of how a crt is driven.
There is no "voltage rating" for a crt, so I have no idea what the numbers 30 and 400 are supposed to mean. He is probably reading off of some data sheet filled with typos. His lack of fundamental knowledge prevents him from ignoring spurious information. A crt has several electrodes, whose voltages should be held within certain limits for safe/satisfactory operation. Rest assured, the Plus and SE have completely compatible crts (both mechanically and electrically). I, and others here, have verified this experimentally countless times, so we're not just making this up.
Just fyi, the Plus/SE crt uses a 12V filament ("heater"), and operates with about 10kV on the final (2nd) anode. For typical voltages on the other electrodes, see http://68kmla.org/files/classicmac2.pdf. Feel free to convey that document to your tech (if you trust him with further work).
Thanks for the reply.
I read over the document you sent me (thanks again for that). The technician I dealt with was probably referring to the Plus' deflection yoke, which is not interchangeable with the SE's CRT. The voltage difference he was referring to does confuse me a bit (one would figure that the voltages would be identical, as the CRTs are identical) however, he has done service work on my 512ke (4 capacitors were replaced on the C circuit as a vertical line appeared on the CRT), and on the SE (the 3.6 volt battery was replaced, and the cooling fan was re-lubricated), and things seem to be working fine after several months since the servicing was completed.
My knowledge on discharging CRTs, and replacing capacitors is very limited (but I intend to learn how to complete these tasks in the near future), hence why I trust the expertise of my TV technician.
I read over the document you sent me (thanks again for that). The technician I dealt with was probably referring to the Plus' deflection yoke, which is not interchangeable with the SE's CRT. The voltage difference he was referring to does confuse me a bit (one would figure that the voltages would be identical, as the CRTs are identical) however, he has done service work on my 512ke (4 capacitors were replaced on the C circuit as a vertical line appeared on the CRT), and on the SE (the 3.6 volt battery was replaced, and the cooling fan was re-lubricated), and things seem to be working fine after several months since the servicing was completed.
My knowledge on discharging CRTs, and replacing capacitors is very limited (but I intend to learn how to complete these tasks in the near future), hence why I trust the expertise of my TV technician.
The yokes are fully compatible between the Plus and SE, mechanically, electrically, and pin-connection-wise.
But even if there were a yoke incompatibility, it would have no bearing on a crt replacement, for one could always replace only the crt, leaving each yoke with its original mac. When swapping crts between Classics and the SE, e.g., this is what you need to do because in that case, the yokes are indeed incompatible.
You should seriously consider doing the operation yourself. It requires no special skills -- just the temperament to work deliberately and carefully, and the ability to follow directions.
But even if there were a yoke incompatibility, it would have no bearing on a crt replacement, for one could always replace only the crt, leaving each yoke with its original mac. When swapping crts between Classics and the SE, e.g., this is what you need to do because in that case, the yokes are indeed incompatible.
You should seriously consider doing the operation yourself. It requires no special skills -- just the temperament to work deliberately and carefully, and the ability to follow directions.
Thank you all for the replies.
Although I do not want to bash my TV technician as being an imbecile, or inexperienced (that was not my intention anyway), I am a hands-on person, and naturally I would appreciate any instructions, which are useful in completing such a task, especially from someone who has transferred CRTs on the compact Macs.
I have opened the case to my 88 Plus several times (I have the original Apple Torx screwdriver to unscrew the case & a case cracker) to take a look around, and to see if that urban legend with the designer's signatures is actually true (and it is). My main concern, of course, is discharging the CRT, since I do not have the proper tools, or knowledge to do so.
Since the forum members who have replied to this post state that the CRTs are indeed compatible, any terminology or resources to backup my case is greatly appreciated, as naturally I would like to discuss this with my TV technician, and complete this task without having to purchase a donor SE.
Although I do not want to bash my TV technician as being an imbecile, or inexperienced (that was not my intention anyway), I am a hands-on person, and naturally I would appreciate any instructions, which are useful in completing such a task, especially from someone who has transferred CRTs on the compact Macs.
I have opened the case to my 88 Plus several times (I have the original Apple Torx screwdriver to unscrew the case & a case cracker) to take a look around, and to see if that urban legend with the designer's signatures is actually true (and it is). My main concern, of course, is discharging the CRT, since I do not have the proper tools, or knowledge to do so.
Since the forum members who have replied to this post state that the CRTs are indeed compatible, any terminology or resources to backup my case is greatly appreciated, as naturally I would like to discuss this with my TV technician, and complete this task without having to purchase a donor SE.
As the author of the CRT FAQ, I concur--the CRT of the Plus (and earlier models) is completely interchangeable with the SE series (all models) and Revision A Classics. Other parts such as analog boards and video boards aren't, but the CRTs themselves can be swapped. (Revision B Classics are the only compacts to use a non-compatible part with the rest of the line, and that part is the actual connector that attaches the CRT to the analog board).
The SE (new-style) and Classic (both types) automatically discharge the CRT. Earlier models supposedly don't; if you want to build a discharge tool there are instructions all over the web. Some prefer to wait for the CRT to discharge on its own by leaving the Mac unplugged and turned off for a few weeks. Even if you do use a discharge tool, it's best to leave the Mac unplugged for a little while.
The SE (new-style) and Classic (both types) automatically discharge the CRT. Earlier models supposedly don't; if you want to build a discharge tool there are instructions all over the web. Some prefer to wait for the CRT to discharge on its own by leaving the Mac unplugged and turned off for a few weeks. Even if you do use a discharge tool, it's best to leave the Mac unplugged for a little while.
and dont do it though the chassis ground, do it from the lugs on the front of the crt
your not really discharging anything, capacitors are most like a tank with a bladder in the middle, fill up one side the bladder expands which also builds up force on that side, if you connect the 2 sides together they will even back out, but "evening out" I guess was too hard for the old timers (like 1930's tv techs) to understand?
letting that force release though the ground plane on any part of the ciruit will most definitely fry something, usually something in the digital - logic areas where its weakest, yea the force of the capacitor (the largest one in the system the CRT tube) is removed, but in the most destructive way possible
its like disarming a 2 part chemical bomb by blowing it up, instead of clipping the green wire to keep it from mixing
Instructions for discharging the crt are in the document I linked to earlier. There's even a photo showing the proper discharge location, as Osgeld alluded to.
No special tool is needed. Don't even bother with a current-limiting resistor -- online advice about this is simply wrong (high-voltage resistors are special; use of ordinary resistors is like using none at all, so might as well keep things simple).
As far as terminology/resources/etc., with which to convince your tech, either he accepts what we say, or he doesn't. It all depends on whether he's sufficiently self-aware to understand his level of ignorance. I have swapped quite a few crts in compact macs, dating back to the late 1980s, and reverse-engineered the analog board (the result of which is the doc I pointed you to). If he's not willing to defer to those with that much greater experience, then just leave it be, and do the job yourself. It'll be less trouble than to convince your tech that all would be well.
Thanks again for the replies.
I will see about swapping the displays myself, and what turns out of it.
I doubt that anyone on this forum is from Southern Ontario (Canada), but if you know someone who lives somewhere within the Greater Toronto Area, and is willing to swap the displays, let me know as soon as possible. The SE will work with the screen-burn (it has for the past 4 + years), but I know that one day that CRT will not turn on.
Out of curiosity, when the CRT on a compact Mac fails (basically reaches the end of its life), and the capacitors/power supply are not the culprit, does it have any effects on any of the Mac's internal components (ie., analog/logic board)?
I will see about swapping the displays myself, and what turns out of it.
I doubt that anyone on this forum is from Southern Ontario (Canada), but if you know someone who lives somewhere within the Greater Toronto Area, and is willing to swap the displays, let me know as soon as possible. The SE will work with the screen-burn (it has for the past 4 + years), but I know that one day that CRT will not turn on.
Out of curiosity, when the CRT on a compact Mac fails (basically reaches the end of its life), and the capacitors/power supply are not the culprit, does it have any effects on any of the Mac's internal components (ie., analog/logic board)?
If this was at my house it would be fun. First check is the CRT part number (Mfr) which are usually long affairs. The easy option is to get an exact replacement. Also check the scan coils, they might have a similar number. I've just looked on my Mac Plus and the numbers are there. Get the same parts and do a swap. As we all know the CRT comes with the scan coils glued on, keep it that way.
I would think all these little Mac CRTs are virtually the same execpt from those with the new diode split EHT transformer (Classic/II) - I would have to do a proper check. The key things are: glass bit - heater voltage, the final anode will be all about the same. The yolk: inductance of the vert/horiz coils, unless you're equipped with a bridge, go by part number.
Basically the horiz yolk inductance needs to have the correct tuning cap, the Plus is 33nF (I recall) maybe the Classic has a diff value. This arrangement is crucial (never change the tuning cap without knowing what might happen - boom).
So once I'd done those simple checks I'd do a CRT swap. Things that could happen (go wrong) fizzing, crack and small blazing pik - EHT too high, turn off! bad swap!
Heaters glow really BRIGHT (orange->yellow->flashbulb bright) - heater voltage wrong, modify. And so on, quite fun. All one hand in trouser pocket and on rubber mat (or wear rubber boots) stuff.
I've never had a CRT go boom on me, a few EHT transformers though. Be careful if it goes wrong there can be some mad voltages lurking which will bite and destroy.
I would think all these little Mac CRTs are virtually the same execpt from those with the new diode split EHT transformer (Classic/II) - I would have to do a proper check. The key things are: glass bit - heater voltage, the final anode will be all about the same. The yolk: inductance of the vert/horiz coils, unless you're equipped with a bridge, go by part number.
Basically the horiz yolk inductance needs to have the correct tuning cap, the Plus is 33nF (I recall) maybe the Classic has a diff value. This arrangement is crucial (never change the tuning cap without knowing what might happen - boom).
So once I'd done those simple checks I'd do a CRT swap. Things that could happen (go wrong) fizzing, crack and small blazing pik - EHT too high, turn off! bad swap!
Heaters glow really BRIGHT (orange->yellow->flashbulb bright) - heater voltage wrong, modify. And so on, quite fun. All one hand in trouser pocket and on rubber mat (or wear rubber boots) stuff.
I've never had a CRT go boom on me, a few EHT transformers though. Be careful if it goes wrong there can be some mad voltages lurking which will bite and destroy.
Don't worry about interceptor2's comments about capacitances, glue and such; they are irrelevant for your compact Macs. The yoke (not "yolk") is gently fixed in place by a weak glue. If you need to remove the yoke, it's not hard to do so, and it's perfectly legitimate to remove the yoke. Interceptor2's advice applies to some color crts, such as the trinitron, where the yoke and crt are carefully matched at the factory, and should be replaced together as a unit. Such considerations do not apply to the monochrome compacts at all. Similarly, the capacitance issue he raises is of no concern; the capacitance is integral with the yoke, so you'll never have to worry about it.
Just to reset things to separate signal from the noise, your donor crt is fully compatible with your recipient Mac, electrically and mechanically. The yokes also happen to be fully compatible. You may freely transplant without worries.
As the classicmac2 doc says, just discharge the crts fully, make sure the power cord has been unplugged from the units, and take care not to snap off the vacuum seal nipple at the base of the crt. Again, if you simply work slowly and carefully, you will have no problem doing the operation yourself. Just read the instructions thoroughly beforehand, prepare a good clean workspace, and you'll be done inside of an hour.
Just to reset things to separate signal from the noise, your donor crt is fully compatible with your recipient Mac, electrically and mechanically. The yokes also happen to be fully compatible. You may freely transplant without worries.
As the classicmac2 doc says, just discharge the crts fully, make sure the power cord has been unplugged from the units, and take care not to snap off the vacuum seal nipple at the base of the crt. Again, if you simply work slowly and carefully, you will have no problem doing the operation yourself. Just read the instructions thoroughly beforehand, prepare a good clean workspace, and you'll be done inside of an hour.
:lol: - your mistake, fundamental, do you actually know how the circuit works? It would seem not.Indeed I might choose to swap CRT yokes becuase that's my business, and colour CRTs are very diff from mono, but that was not being disussed here. But to the average guy wanting to do the job, it can bring complications.
yoke vs yolk - typo in the rush to type, must have been the egg sandwich I was eating, Gosh some ppl.
I'm not going to enter into a flame war, I can see you are impressed by my knowledge and feel threated, here we go geek wars "I know more than you"
) cue flames...
The issue is one of providing information to the OP so that he can get his Mac fixed. The information I gave is correct: There is no incompatibility between the Plus and SE CRTs and yokes at all. He can swap them freely without worries. That's the only information he needed. Your post muddied the waters with extraneous, irrelevant information and correction was therefore needed. Don't take offense at the correction. Our job here is to post helpful information to those who ask for it.I'm not going to enter into a flame war, I can see you are impressed by my knowledge and feel threated, here we go geek wars "I know more than you"
cue flames...
I agree with tomlee. The main goal here is to help and inform. For someone who is unfamiliar with a topic the minimal amount of information needed to comprehend the basics of a given subject or make an informed decision is a sensible approach. If the person requests more detailed information it can be freely given in a follow-up post.
Fellas, fellas,
The objective here is not to create an online war. Naturally, I deeply appreciate all of the replies that I received on this forum. It's good to know that there are still people out there who continue to appreciate these computers (despite their vulnerabilities).
In regards to my TV tech friend, at least he took the initiative to take a look at these machines (and service one which was in desperate need of repair), because let's face it- these computers are obsolete, and there are many people who would simply turn away at repairing these units, either because it is not "economically worth it," or because the knowledge base is not there. I know, since I have been turned away by others who simply ask: "Why do you still have this piece of....?" and I am sure many people on this forum site have faced this problem as well, hence why we have all taken the initiative to learn how to repair our vintage Macs (and effectively, too!).
It's great to finally have confirmed that these CRTs are indeed compatible. When I have time (and I mean ample time to actually do the job properly, as I have never completed such a task before), I will get this done. The SE is a very reliable computer, but like all electronics, parts ultimately require service.
The objective here is not to create an online war. Naturally, I deeply appreciate all of the replies that I received on this forum. It's good to know that there are still people out there who continue to appreciate these computers (despite their vulnerabilities).
In regards to my TV tech friend, at least he took the initiative to take a look at these machines (and service one which was in desperate need of repair), because let's face it- these computers are obsolete, and there are many people who would simply turn away at repairing these units, either because it is not "economically worth it," or because the knowledge base is not there. I know, since I have been turned away by others who simply ask: "Why do you still have this piece of....?" and I am sure many people on this forum site have faced this problem as well, hence why we have all taken the initiative to learn how to repair our vintage Macs (and effectively, too!).
It's great to finally have confirmed that these CRTs are indeed compatible. When I have time (and I mean ample time to actually do the job properly, as I have never completed such a task before), I will get this done. The SE is a very reliable computer, but like all electronics, parts ultimately require service.
The main purpose of these message boards is to be helpful, there is a lot of ppl with useful knowledge. I was unimpressed by the previous remark, I design monitors professionally so for someone to dismiss my technical statement and replace it with a wrong one, well really. )
I could give full detailled analysis on EXACTLY how the deflection circuit works, with calcs etc. but it is such an detailled and in depth subject this message board is the wrong place for it.
The orginal question is best answered with Bunsen's link.
) I could give full detailled analysis on EXACTLY how the deflection circuit works, with calcs etc. but it is such an detailled and in depth subject this message board is the wrong place for it.
The orginal question is best answered with Bunsen's link.
Just to give an update-
I spoke to my physics teacher about the issues pertaining to the CRT compatibility. Although his knowledge on vintage Macs is limited (he was a Commodore guy in his youth, or so I have been told), he states that perhaps the voltage difference that the TV tech was referring to could perhaps be the result of fluctuation in the power supply, or flyback transformer, which is causing an inbalance of some sort. Either than that, he was surprised to hear that a voltage difference could even have existed between two identical CRTs.
I currently have the Plus for sale, as the logic board, and floppy drive are sure to be of some use to someone who wants to upgrade their 128/512, or repair their Plus. I just have not had the time to complete this task.
Let me know what you guys think about this theory.
I spoke to my physics teacher about the issues pertaining to the CRT compatibility. Although his knowledge on vintage Macs is limited (he was a Commodore guy in his youth, or so I have been told), he states that perhaps the voltage difference that the TV tech was referring to could perhaps be the result of fluctuation in the power supply, or flyback transformer, which is causing an inbalance of some sort. Either than that, he was surprised to hear that a voltage difference could even have existed between two identical CRTs.
I currently have the Plus for sale, as the logic board, and floppy drive are sure to be of some use to someone who wants to upgrade their 128/512, or repair their Plus. I just have not had the time to complete this task.
Let me know what you guys think about this theory.
Your physics teacher's hypothesis makes no sense. He may be a good high school physics teacher, but he clearly knows next to nothing about the physics of CRTs, if he's talking about "imbalances" and "voltage fluctuations" as having any relation to CRT voltage ratings. In trying to make sense out of your tech's nonsense, he's made up nonsense of his own, unfortunately.
Once again, there is no incompatibility among the CRTs of compact Macs. None. Again, I've swapped many over two decades of working on Macs, from 128K models to the Classic II, and there are many on this site who have done the same. There is thus plenty of experimental support for the assertion of compatibility, and there is zero contrary data. That's as scientifically supported as it gets.
Once again, there is no incompatibility among the CRTs of compact Macs. None. Again, I've swapped many over two decades of working on Macs, from 128K models to the Classic II, and there are many on this site who have done the same. There is thus plenty of experimental support for the assertion of compatibility, and there is zero contrary data. That's as scientifically supported as it gets.
To echo what other brilliant posters have said, the deflection yoke is the holdup. To offer a unique perspective, a similar problem is bedeviling me with a Macintosh 128k, serial number F4410PMM0001. The symptoms ate slightly different and the cause is also slightly different, but it is in the same general category. The difference is I don't have a vintage TV repair-person in my neck of the woods (Chattanooga, TN 37412-2718) that can A) cross-over to work on vintage computers; B) repair a 128k specifically; and C) offer a warranty. You have such good fortune that you have someone who fits all three of those categories, and I am praising the Lord I believe in wholeheartedly that you at least can have what I am so desperately seeking.
Hope this helps and have a great day!
Hope this helps and have a great day!
hey I clicked on bunsens link... and this part here:
So anyone know where to get these tools? because i used a regular metal allen key wrench to adjust the tuning coil in my CC yoke and it cracked and fell apart, i need plastic i assume.
So i will have to find these tools, and get a new tuning slug.
Sorry for hijacking, just a heads up since this is a CRT thread.
Well, the link they provided is dead now.
So anyone know where to get these tools? because i used a regular metal allen key wrench to adjust the tuning coil in my CC yoke and it cracked and fell apart, i need plastic i assume.
So i will have to find these tools, and get a new tuning slug.
Sorry for hijacking, just a heads up since this is a CRT thread.
I do have this Radio Shack set, but right now it's in storage with some infrequently-used tools. When I had to adjust a compact CRT a few months ago, I used the following:
1. For the standard slotted dial, a small eyeglasses screwdriver works well. Width is a slight problem, but if you're patient it should be fine. Make sure you insulate your tool with electrical tape.
2. For the hex, which is a plastic tool in the RS kit, you're going to be hard-pressed to find anything that fits. However, a little creativity goes a long way. I took an old plastic-handle watercolor brush, used 120 grit sandpaper to shape it, and after a little playing around it was able to turn the control without a problem. Make sure you use a brush with a thin handle at the end--you need something far thinner than a standard pencil. I could see a heavily sanded/filed Bic pen cap working too.
I did try an allen wrench, but mine was the wrong size. I'd take Techknight's advice and not attempt one.
If you do want real TV tools, the best place to look would be one of those independent TV retailers specializing in service. They may have some for the DIYers among us. Hardware stores, namely the mom-and-pop ones with plenty of old stock, may also be a good source. (Not to get anyone's hopes up, but I once found Duracell brand Mac Plus/512K/128K clock batteries at one, so anything is possible).
1. For the standard slotted dial, a small eyeglasses screwdriver works well. Width is a slight problem, but if you're patient it should be fine. Make sure you insulate your tool with electrical tape.
2. For the hex, which is a plastic tool in the RS kit, you're going to be hard-pressed to find anything that fits. However, a little creativity goes a long way. I took an old plastic-handle watercolor brush, used 120 grit sandpaper to shape it, and after a little playing around it was able to turn the control without a problem. Make sure you use a brush with a thin handle at the end--you need something far thinner than a standard pencil. I could see a heavily sanded/filed Bic pen cap working too.
I did try an allen wrench, but mine was the wrong size. I'd take Techknight's advice and not attempt one.
If you do want real TV tools, the best place to look would be one of those independent TV retailers specializing in service. They may have some for the DIYers among us. Hardware stores, namely the mom-and-pop ones with plenty of old stock, may also be a good source. (Not to get anyone's hopes up, but I once found Duracell brand Mac Plus/512K/128K clock batteries at one, so anything is possible).
In regards to Quicksilvermacs comment, the TV tech only bothered to repair/inspect my 3 compact Macs because they all suffered (with the exception of one now) from well-known TV problems. An analog board in a compact Mac in principle is no different from an analog board in a TV (despite their physical features of course), and the same goes with how a CRT operates. Naturally, if these Macs were suffering from logic board problems, then perhaps this fellow would have advised me to go to someone more qualified with computers.
Furthermore (and let's face facts here) TV repair as a practice is unfortunately becoming a dying breed. Nobody wants to spend extra money repairing their equipment (unless they are able to complete the task themselves), and the computers being sold now are either not worth repairing (as they become obsolete within the year, or the warranty has expired), or are not user-servicable (like the current MacBook series).
Quicksilvermac, I would like to hear more about the problem you are experiencing with your 128k. If you want to PM me, feel free to do so.
Furthermore (and let's face facts here) TV repair as a practice is unfortunately becoming a dying breed. Nobody wants to spend extra money repairing their equipment (unless they are able to complete the task themselves), and the computers being sold now are either not worth repairing (as they become obsolete within the year, or the warranty has expired), or are not user-servicable (like the current MacBook series).
Quicksilvermac, I would like to hear more about the problem you are experiencing with your 128k. If you want to PM me, feel free to do so.
For turning the ferrite cores inside inductors, one generally should use a nonconductive tool. This recommendation becomes a mandate for inductors used in horizontal deflection circuits. So, even if you find a hex wrench that fits, you will find that the mere insertion of the tool into the core will perturb the adjustment. In severe cases, you will kill the circuit.
As the pdf doc suggests, you can fashion a suitable tool from cheap chopsticks. Just whittle one down to slightly greater than the final diameter, and gently push it into the core. Cheap chopsticks will readily conform to the hexagonal shape, but retain enough strength to make the adjustment.
As the pdf doc suggests, you can fashion a suitable tool from cheap chopsticks. Just whittle one down to slightly greater than the final diameter, and gently push it into the core. Cheap chopsticks will readily conform to the hexagonal shape, but retain enough strength to make the adjustment.
After reflecting on your friends' theories a bit further, I think I've figured out what they were thinking. It seems that I've overlooked the possibility of a mismatch in relative humidity specs. If the Aquadag formulations are designed for different RH, then there can be a large fluctuation in flyback inertia, causing an electron pile-up in the 2nd-anode area. But this won't cause any damage to your Mac. True, it might cause electron "whiplash" Bremsstrahlung, but that is a consideration only in esoteric corners of E&M theory (I'm sure your physics teacher can expand on this if you are interested), and has no practical bearing on your repair challenges. So, again, feel completely free to swap crts (but not necessarily deflection yokes) from one compact Mac to any other.
It's best to keep the deflection yoke with its original analog board if one is unsure of compatibility. The only problem arises when transplanting between Classics and the compacts that preceded them. Within Classics or within the other compacts, the yoke can be kept on the crt and the pair transplanted as an ensemble.
But if one wants a simply-stated universal rule that doesn't require remembering any of the above, "it's safe to transplant just the crt from any compact mac to any other compact mac" is it. Following it avoids compatibilty problems completely, but can force you to separate a yoke from its crt unnecessarily (and obligate you to additional post-transplant adjustments that then become needed).
But if one wants a simply-stated universal rule that doesn't require remembering any of the above, "it's safe to transplant just the crt from any compact mac to any other compact mac" is it. Following it avoids compatibilty problems completely, but can force you to separate a yoke from its crt unnecessarily (and obligate you to additional post-transplant adjustments that then become needed).