Thread
Just purchased Mac 512k
It's the homeopathic approach, I guess ;-)Indeed, since UV light is one of the causes of case-yellowing, isn't it at least slightly perverse to try to accelerate the production of nascent O to remove yellowing with the same agent that has already been responsible for the yellowing?
Mainly aimed at equill: Two theories. Is it possible that bleaching case plastics works by modifying the "colour" of fillers such as calcium carbonate? An oxidizer cannot easily change the filler (in original state) chemically, but may reverse other contaminants.
Calcium carbonate has its own luminescent properties that we may not understand in conjunction with ABS. Perhaps if you oxidize surface dirt discolouration (ie not the ABS itself), sufficient light will penetrate that you don't see ABS discolouration. Sharp, tiny crystals can reflect an awful lot of light.
Calcium carbonate has its own luminescent properties that we may not understand in conjunction with ABS. Perhaps if you oxidize surface dirt discolouration (ie not the ABS itself), sufficient light will penetrate that you don't see ABS discolouration. Sharp, tiny crystals can reflect an awful lot of light.
There is plenty of anecdotal evidence, here and elsewhere, that a variety of actions can produce temporary respite in case-yellowing. I write 'respite' because some amount of yellowing is removed. I do not use 'reversal' because that is impossible. The newly-exposed less- or un-yellowed plastic is now the virgin and unprotected lamb among the lions of atmosphere, irradiation, solution, heat, grunge and what-have-you. Only an impervious coating or an inert environment can preserve the new status quo of case-condition, else begins again the deterioration of the topmost surfaces of the ABS.
'Twas ever thus. It is somewhat forlorn to suppose that a disposable case material that was not intended to last forever can be induced, after the event, to become imperishable.
de
'Twas ever thus. It is somewhat forlorn to suppose that a disposable case material that was not intended to last forever can be induced, after the event, to become imperishable.
de
I for one am fully aware that the plastics will yellow again. And indeed, they will likely yellow under the same conditions (heat, UV light, presence of smoke, etc.). But the "big deal" for me is that with this technique, you can make the plastics "look like new." No, not just take away "a little bit of the yellowing." From what I see, it takes MOST of it away. And as I posted earlier, even if it takes a few years for that yellowing to come back, I can enjoy a rather "new looking" case during that time, and then repeat the process again to remove the yellowing again.
So while it does not stop yellowing, it does appear to kill it for as long as you wish to repeat the process. And while I am sure there must be some "limit to it," it is unlikely to be reached in my lifetime. (For if one repeats the process every 3 years for 40 years, that's a mere 13 times.)
So while it does not stop yellowing, it does appear to kill it for as long as you wish to repeat the process. And while I am sure there must be some "limit to it," it is unlikely to be reached in my lifetime. (For if one repeats the process every 3 years for 40 years, that's a mere 13 times.)
Yes that raises an interesting point. As does JDW.2) coat the ABS plastic with UV-opaque clear finish, and to keep the cases away from heat and further UV-irradiation
If you coat the case with a UV coating, while it might be possible to keep it away from most UV sources, if one intends to use it, the heat the unit itself produces would most likely initiate the yellowing process. Therefore, you'd have a case that yellowed from under the UV coat.
As JDW points out, one could continue to "clean" a case over the life of one's possession of it, but if it is coated, that would effectively end the ability to de-yellow it further. Truly then the only way to preserve it once, cleaned would be to display it under UV glass in a temperature controlled environment and never use it.
Jobs may well be onto something with that unibody aluminum. If only he had a nostalgic streak for the rest of us.
I can't help but wonder what the limit is to "refreshing" an old Mac case. It would be helpful to know what is actually happening during the process and whether any damage is actually occurring to the plastic, such as brittleness or texture abrasion.
One last thought, the Vintage Computer article indicated that companies were aware of the color problem (and Apple was already acutely aware of the Lisa 1's tendency to turn orange, per Kunkle's AppleDesign), and added more blue to the mix which would mitigate the potential to yellow for some additional time. This might explain why in this thread Sanman observes that the documented PMS 453 Mac color chip was more green than an unopened pristine keypad. It only now also occurs to me that an unopened keypad is not immune to the effects of yellowing simply because it is not exposed to the air and UV, and that the actual color of the final factory plastics is somewhat less yellow than his keypad and somewhat less green that the PMS chip.
Update on getting the 512K up and running.
To recap - I received the 512K and it would start/run for about a minute and then shut down with a buzzing noise followed by a repeated "whup", "whup" cycling noise. I removed the case cover and found that flexing the analog board would get momentary return of power. Given that movement restored power, some participants in these forums thought "dry joints" may be the culprit. I desoldered/resoldered many of the components on the analog board - but the same problem persisted.
So I ordered a known working/used analog board. Hooked it up Tuesday. SAME EXACT problem. Crap - but.... that's progress at least (Analog board is likely not the problem). I disconnected the CRT and powered up just the analog and logic board.... same problem/sounds.... So it was looking like the logic board was the culprit. From what I read in Pina's book - I was hearing what is refered to as a "flupping noise" - which apparently happens when the analog board protects itsleft from too much power. Sometimes caused by shorted circuits (among other things).
So I start to think about it and recalled that, when I first inspected this mac, there appeared to have been some liquid spilled down the back right-side of the unit. It was a small amount, but it had flowed around the AppleTalk connection. I had cleaned it up and forgot about it. I pulled the logic board and looked closely and found that there was some dried/flaking corrosion around the AppleTalk port on the board. I also noted that flexing the analog board would actually flex the logic board in this area... So I decided to clean that area of the logic board - but I could not really get to it.
Hmmm - somewhere on these boards I saw a post about washing a logic board. Searched... yup - people have washed their logic board and found it fixes some problems.... Many recommended the dishwasher - no soap. So I tried it. Then left it in front of a fan for a day to ensure it was dried out.
Got home last night - hooked everything up. BINGO - a rock-solid working Mac 512K! Adjusted the video and voltage pot. All good.
So I hooked up the HD20 that I purchased on eBay and installed System 6.0.8 and have been playing - good stuff! I have been able to use an older Mac 8600 with a CD and floppy drive to download software and move it onto a floppy - then onto my Mac.
New problem. I put the PRAM battery in last night. I've tested the battery and it works - but the Mac will not accept my date and time input. As soon as I click out of the time/date fields it resets to the default time/date.
Any advice? Is the PRAM chip dead? The battery connection to the board looks ok and tests ok.
To recap - I received the 512K and it would start/run for about a minute and then shut down with a buzzing noise followed by a repeated "whup", "whup" cycling noise. I removed the case cover and found that flexing the analog board would get momentary return of power. Given that movement restored power, some participants in these forums thought "dry joints" may be the culprit. I desoldered/resoldered many of the components on the analog board - but the same problem persisted.
So I ordered a known working/used analog board. Hooked it up Tuesday. SAME EXACT problem. Crap - but.... that's progress at least (Analog board is likely not the problem). I disconnected the CRT and powered up just the analog and logic board.... same problem/sounds.... So it was looking like the logic board was the culprit. From what I read in Pina's book - I was hearing what is refered to as a "flupping noise" - which apparently happens when the analog board protects itsleft from too much power. Sometimes caused by shorted circuits (among other things).
So I start to think about it and recalled that, when I first inspected this mac, there appeared to have been some liquid spilled down the back right-side of the unit. It was a small amount, but it had flowed around the AppleTalk connection. I had cleaned it up and forgot about it. I pulled the logic board and looked closely and found that there was some dried/flaking corrosion around the AppleTalk port on the board. I also noted that flexing the analog board would actually flex the logic board in this area... So I decided to clean that area of the logic board - but I could not really get to it.
Hmmm - somewhere on these boards I saw a post about washing a logic board. Searched... yup - people have washed their logic board and found it fixes some problems.... Many recommended the dishwasher - no soap. So I tried it. Then left it in front of a fan for a day to ensure it was dried out.
Got home last night - hooked everything up. BINGO - a rock-solid working Mac 512K! Adjusted the video and voltage pot. All good.
So I hooked up the HD20 that I purchased on eBay and installed System 6.0.8 and have been playing - good stuff! I have been able to use an older Mac 8600 with a CD and floppy drive to download software and move it onto a floppy - then onto my Mac.
New problem. I put the PRAM battery in last night. I've tested the battery and it works - but the Mac will not accept my date and time input. As soon as I click out of the time/date fields it resets to the default time/date.
Any advice? Is the PRAM chip dead? The battery connection to the board looks ok and tests ok.
I don't think you ever mentioned the "whup", "whup" noise, just the buzzing. That's a dead giveaway. :beige: Most likely in the area you describe you had a substance that was shorting the reset switch or power connector. I cannot for the life of me figure out how flexing the powerboard affected the logicboard, unless the connector cable was moving just enough to flex the logicboard connector (as they are both rigidly isolated by the chassis).it would start/run for about a minute and then shut down with a buzzing noise followed by a repeated "whup", "whup" cycling noise. ... I was hearing what is refered to as a "flupping noise" - which apparently happens when the analog board protects itsleft from too much power. Sometimes caused by shorted circuits (among other things).
I also noted that flexing the analog board would actually flex the logic board in this area...
Any advice? Is the PRAM chip dead? The battery connection to the board looks ok and tests ok.
As for the time settings, it may not be a hardware problem since that info is also stored in active RAM when the power is on and the RTC is responsible for triggering the active clock. The battery only powers the RTC when the mains are shut down and has nothing to do with active RAM settings. Try starting off the floppy disk only and see if you can set the time (if you have an earlier system try that as well). Also, change other settings in the control panel and see if any of those (like volume) reset before or after restart. It is possible that System 6.0.8 writes more P-RAM data than the 512K's limited 20 byte RTC chip will accommodate (the Plus had 256 bytes). I would try zapping the P-RAM. Hopefully that will force a wipe of the current data and let 6.0.8 write new data in the order you set it. If none of that works, I suppose some kind of bit-rot could be affecting the chips RAM.
512K:
My original analog board did not always produce the "whup, whup" noise - which is why I did not focus on that - it generally started and ran fine but degraded after a minute or so and then would sometimes make that noise if I tried to restart. The replacement analog board consistantly made that noise - which helped to narrow down the cause.
Regarding the flexing - where the rear of the analog board is attached (via two screws), pressure on that area also puts pressure on the logic board - right where the apple talk port is... Enough to move it and perhaps break any short circuit temporarily (I'm only guessing)?
Regarding the PRAM - I did boot off of the system 1.1g floppy and was not able to set the time... This was an issue prior to installing system 6.0.8. I can change the mouse speed settings and they seem to hold - until reboot - then all settings are lost. Any changes to the time/date immediately revert back to defaults... I'll further trouble shoot and see what I find. I'm away until Sunday - I'll report back.
Great idea to reset the PRAM - I'm away until Sunday - I will give that a shot.
My original analog board did not always produce the "whup, whup" noise - which is why I did not focus on that - it generally started and ran fine but degraded after a minute or so and then would sometimes make that noise if I tried to restart. The replacement analog board consistantly made that noise - which helped to narrow down the cause.
Regarding the flexing - where the rear of the analog board is attached (via two screws), pressure on that area also puts pressure on the logic board - right where the apple talk port is... Enough to move it and perhaps break any short circuit temporarily (I'm only guessing)?
Regarding the PRAM - I did boot off of the system 1.1g floppy and was not able to set the time... This was an issue prior to installing system 6.0.8. I can change the mouse speed settings and they seem to hold - until reboot - then all settings are lost. Any changes to the time/date immediately revert back to defaults... I'll further trouble shoot and see what I find. I'm away until Sunday - I'll report back.
Great idea to reset the PRAM - I'm away until Sunday - I will give that a shot.
Since the dishwasher has been mentioned again, I would like to add that the SE/30 is not the only machine in need of logic board re-capping. The capacitors on the original 128k and 512k motherboards could use replacement as well. Indeed, I replaced the caps on my 512k board and found that some minor screen anomalies went away. For this reason, I have put the capacitor values at the bottom of my analog board parts spreadsheet.
I still don't quite follow the flexing issue, but so long as it works now.I can change the mouse speed settings and they seem to hold - until reboot - then all settings are lost. Any changes to the time/date immediately revert back to defaults...
The fact that the settings take in RAM and the clock keeps good time, other than not being able to be set, could mean that the PRAM battery connection is not making it to the logicboard. Pin 11 (opposite the keyed end of the power connector) carries the battery power to the board. Check continuity via the pin and the RTC chip. Battery power enters the RTC chip (CLK) via pin 8 (closest to the CPU). If all is well there, the battery contacts may have some corrosion where it attaches to the analogue board, so check continuity between Pin 11 and the battery on the analogue board.
But first try to reset the PRAM. If that fails and power is getting to the RTC chip, then you may well have some kind of bit-rot in the 20 bytes of RAM and the RTC chip will need to be replaced. Not sure how easy that will be without cannibalizing another board.
UPDATE: To reset the PRAM, visit Charlieman's excellent website and review the Power User Manual's excerpts. Do a page search for "parameter" to quickly find the section on resetting your PRAM.
Jags House Also has rounded up some tips from around the web. And offers some additional advice. I'm actually not sure the exact way to do this on a 128K-Plus, so you should try all the methods.
I would further try setting the clock time, then immediately closing the Control Panel, rather than clicking outside the clock settings field. Perhaps that will retain the settings. It is unlikely installing a PRAM battery upside down would harm the board, but anything is possible.
JDW - excellent spreadsheet.Since the dishwasher has been mentioned again, I would like to add that the SE/30 is not the only machine in need of logic board re-capping. The capacitors on the original 128k and 512k motherboards could use replacement as well. Indeed, I replaced the caps on my 512k board and found that some minor screen anomalies went away. For this reason, I have put the capacitor values at the bottom of my analog board parts spreadsheet.
We both were mentioned in the latest retromaccast: http://cdn4.libsyn.com/retromaccast/RetroMacCast_103__Sonata.m4a
Have you given the de-yellowing process a try?
James & John have honored me with a mention in a couple more past episodes of RetroMacCast too. I certainly enjoy their program.
I've not tried the de-yellowing process yet because I cannot find all the ingredients here. Yes, we have 3% bottles of peroxide here, but I would need to have a relative or friend send me a tub of that "OxiClean Stain Remover." I'm quite eager to try it once I can obtain the OxiClean!
I've not tried the de-yellowing process yet because I cannot find all the ingredients here. Yes, we have 3% bottles of peroxide here, but I would need to have a relative or friend send me a tub of that "OxiClean Stain Remover." I'm quite eager to try it once I can obtain the OxiClean!
JDW, I would be shocked if Japan did not have a similar "Oxy" product. It is simply a mixture of sodium percarbonate and sodium carbonate or "soda ash". Look in the laundry section of your shops for "whiteners" which contain only these ingredients. That will be the stuff.but I would need to have a relative or friend send me a tub of that "OxiClean Stain Remover." I'm quite eager to try it once I can obtain the OxiClean!
If you insist on the name brand, you can just check out their website. Perhaps they will ship to Japan. However, their website verifies that their product is fully biodegradable that breaks down to oxygen and soda ash, with a little bit of blue food coloring.
Well, it's closer to two weeks now, so sorry for the delay (I've been pretty flat out of late) — that said, I've only received one message on this subject, and that was on the RetroMacCast site.I wouldn't take it personally, it's only been 8 days. :beige:I wrote Peter Dreisiger twice asking for the exact substance he used, but he must have fallen off the face of the planet because he refuses to reply.
Mmmm. I might be wrong here, but given that the manufacturer only lists Australian and New Zealand contact numbers, I too would be surprised if they exported their products to Japan.From reading his post, I am not sure having the exact brand would be helpful to you in Japan, though Pacific rim products might be common. However, I think he is referring to a standard pre-mix hair salon peroxide coloring treatment, essentially the same formula described in the link he references. That link basically describes how to make a similar gel. I would suggest going to a hair salon supply store and asking for a generic peroxide gel, then compare a few for ingredients.
Anyway, to add a couple of points to the discussion, the gel I've used (thus far) contains a mixture of hydrogen peroxide (12% V/V) and phosphoric acid (concentration unknown), and, while it has produced some good results, it has also left a bit of spotting (probably from variations in the thickness of gel).
Like I said, I've been a little flat out of late, but once things settle down a bit, I am going to try using a straight solution (assuming I can find a retail supplier); while the gel is probably better suited to pieces of plastic that are too large or awkward to immerse in a tub of peroxide, I suspect that the solution will give better, and more consistent results.
If I get around to this before the thread winds up, I can post some details and comparisons here.
Cheers,
Pete
Like old soldiers, these threads never die. They are always lurking around somewhere deep in the forum archives. :beige: (not as eloquent as MacArthur's speech, but you get the point).If I get around to this before the thread winds up, I can post some details and comparisons here.
I'm sure we all look forward to your results whenever they come! Just look up the thread and it'll be like it never faded away.
Mac 128 - Thanks for updating your post on resetting the PRAM. So far, no luck via the reset method....
I've tried booting from System 1 (via Disk) and System 6.0.8 (HD20) - the clock settings and date settings revert to default when closing the control panel or moving to another setting within control panel - after changing the date or time.
I found another symptom - if I select Alarm Clock from the Apple menu, the OS freezes up... I wonder if anyone else would not mind trying to remove their battery and seeing if their 128K or 512K Mac responds the same way (freeze on launch of Alarm Clock and/or reverts to defaults when entering time/date).
My multimeter is not available at the moment - I leant it to a friend and will test some of the battery flow tomorrow.
I've tried booting from System 1 (via Disk) and System 6.0.8 (HD20) - the clock settings and date settings revert to default when closing the control panel or moving to another setting within control panel - after changing the date or time.
I found another symptom - if I select Alarm Clock from the Apple menu, the OS freezes up... I wonder if anyone else would not mind trying to remove their battery and seeing if their 128K or 512K Mac responds the same way (freeze on launch of Alarm Clock and/or reverts to defaults when entering time/date).
My multimeter is not available at the moment - I leant it to a friend and will test some of the battery flow tomorrow.
Real Time Clock failures in other models have been discussed here previously (use the search). This sounds like RTC to me.
Hmmmm - searched for "RTC" already and found nothing of any great help.
Searching on "Real and Time and Clock" - nothing jumping out at me in the search results that I see...... I'll keep poking around.
Charlie
Searching on "Real and Time and Clock" - nothing jumping out at me in the search results that I see...... I'll keep poking around.
Charlie
Ditto. In fact searching for it on Google turns up nothing pertaining to this issue. I don't recall seeing it come up here, so I took a look at the old archives (which are unsearchable) and found nothing there either.Hmmmm - searched for "RTC" already and found nothing of any great help....Searching on "Real and Time and Clock" - nothing jumping out at me in the search results that I see.
I take it the RTC is prone to failure in old Macs? If so, are there replacement options aside from cannibalizing old boards?
I forgot to mention Old SoftWare.Com as an online place to buy new-in-box & used boxmax software, too. lol
Sorry sorry for the mixup!
Once again -- the 3 online stores are ....
1] MacTreasures
2] Old SoftWare.Com
3] B & R Computer Services
:b&w:
Sorry sorry for the mixup!
Once again -- the 3 online stores are ....
1] MacTreasures
2] Old SoftWare.Com
3] B & R Computer Services
:b&w:
That's the one I found too. However, I don't think the problem is the same, though the solution may be. Big Bird's clock would not count normally, a problem which lumpydog does not seem to be having. His software interface seems to have a problem writing to the PRAM itself, even though it maintains other settings, even following power down. Wally does bring up some interesting points about the VIA routing signals into and out of the RTC. I don't pretend to understand the intricacies involved in the discrepancy preventing the retention of the clock setting vs. others though. Or for that matter how the PRAM chip stores data. Could it be that the chip suffers from bit-rot and the portion of the RAM where the clock settings are stored is physically inaccessible (assuming it stores specific data in a specific order like regular RAM). Does the ROM startup routine check the PRAM as well?Wally makes a few good point re RTC in this thread:http://68kmla.org/forums/viewtopic.php?t=686
The fact that going through the dishwasher solved another seemingly unrelated problem, suggests that there might be something else impeding the clock settings on the board, assuming they travel different signal paths than the mouse and volume settings.
Involving only 8 pins to solder, I would think the RTC should be replaced at this point baring any other input. Perhaps just de-soldering the chip, cleaning underneath it and replacing it will be enough.
I've been quite curious about this since your original posting. I spoke with my father recently about that Oxiclean, and when used on clothing stains he said it "works wonders." So despite Mac128's encouragement for me to use another brand, I asked my father to send me a small tube of the stuff, as I have two small children with attire stained badly enough to warrant a dose! Plus, with Lumpydog's technique working wonders with virtually no H202 at all (less than 1.5%, from what I see), I can't help but wonder if that OxiClean isn't doing most of the job on its own.The apple logo can be damaged by this process (as shown in one of the threads I read about this process) be sure to pop out the apple logo on any parts with the apple rainbow colored logo - there is a hole behind it that you can use to pop the logo out - it is held on with a double sided clear sticky pad - light/persistent pressure from behind will pry it lose. The paper label with serial number on my mouse was not effected. Here is a logo that was damaged during this process: http://farm4.static.flickr.com/3175/2976915302_c7147f084e.jpg?v=0
Anyway, I've been worried about the labels because I plan to dip the chassis of my SE/30 in this miracle mixture. While not seen in any of the photos I've placed on Flickr, there is a patch of yellowing toward the back of the case, just above the analog board. It's clear that heat has caused this. I am also curious to see if the OxiClean mixture will make the entire case go back to the new platinum color UNIFORMLY. I certainly don't want to see the yellowing be reduced to the same degree in all places, leaving the machine looking spotty as it does now.
At the same time, I don't want to see my labels damaged or peel off either. And while the label on Lumpy's mouse was apparently not affected, I am curious if all labels will fair so well. I'm also curious how the gray colored paint on the inside of the compact Mac's housing will do after a few hours soaking in this mix. I don't see why labels would be completely unaffected when the Apple logo stands to be utterly destroyed as shown in the photo Lump links too. That's frightful!
I am excited about the potential from this yellow-killing mixture, but quite anxious about it too!
JDW:
A few comments:
1) I have experienced no collateral damage thus far. That is to say, no logos, screened on labels or serial number labels have been harmed or faded. I did remove the square Apple logo from my HD20 case by popping it out of the case (push from the hole behind it). I personally think the guys in the de-yellowing thread, that I linked to earlier, have been using WAY overkill solutions at 30-40% Hydrogen Peroxide. I'm pretty sure at the 3% to 1.5% solution that I've used, the color apple logo would have been fine without removal. The paper label on the bottom of my mouse and the serial number label on my HD20 look fine.
2) If you cant remove the logo, you might try masking tape... I have not yet tried this approach - I would not recommend it over a paper label.
3) Regarding uneven yellowing and uniformity after the process. I promise you will be amazed. My HD20 had the footprint of the Mac that sat atop it... a halo of yellow around it (see pictures). You can't find it now - no trace - zero. My mouse had some deep yellow spotting (see the pictures). No sign of it now. By the way, the pictures really don't do justice to the result.
4) The insides of the HD20 case (same finish as the Mac case) was not effected in any way that I can see.
At the diluted levels that I've used, I've seen highly effective results and no damage to innocent parts/pieces. I'm excited for someone else to try this - the results are extremely gratifying and worth the hassle to find a the H202, Oxi, a clear tub and a sunny day. It's WAY to easy and appears to be non-damaging in any way.
I'm going to do my 512K Mac case this weekend (big clear tub that I have in my attic) and will post results. I am going to just pop out the apple logo. I'll let you know how the rear plastic label and the paper serial number label fair. It will be a very diluted mix... I'll post pictures.
Lumpy
P.S. To everyone else - I'm trying to find some time to tackle the RTC issue. I have just not had time.... One thing I did notice is the the R16 (capacitor?) which is next to the RTC chip, appears to maybe be compromised. It's hard to tell because these things are so damn tiny.
A few comments:
1) I have experienced no collateral damage thus far. That is to say, no logos, screened on labels or serial number labels have been harmed or faded. I did remove the square Apple logo from my HD20 case by popping it out of the case (push from the hole behind it). I personally think the guys in the de-yellowing thread, that I linked to earlier, have been using WAY overkill solutions at 30-40% Hydrogen Peroxide. I'm pretty sure at the 3% to 1.5% solution that I've used, the color apple logo would have been fine without removal. The paper label on the bottom of my mouse and the serial number label on my HD20 look fine.
2) If you cant remove the logo, you might try masking tape... I have not yet tried this approach - I would not recommend it over a paper label.
3) Regarding uneven yellowing and uniformity after the process. I promise you will be amazed. My HD20 had the footprint of the Mac that sat atop it... a halo of yellow around it (see pictures). You can't find it now - no trace - zero. My mouse had some deep yellow spotting (see the pictures). No sign of it now. By the way, the pictures really don't do justice to the result.
4) The insides of the HD20 case (same finish as the Mac case) was not effected in any way that I can see.
At the diluted levels that I've used, I've seen highly effective results and no damage to innocent parts/pieces. I'm excited for someone else to try this - the results are extremely gratifying and worth the hassle to find a the H202, Oxi, a clear tub and a sunny day. It's WAY to easy and appears to be non-damaging in any way.
I'm going to do my 512K Mac case this weekend (big clear tub that I have in my attic) and will post results. I am going to just pop out the apple logo. I'll let you know how the rear plastic label and the paper serial number label fair. It will be a very diluted mix... I'll post pictures.
Lumpy
P.S. To everyone else - I'm trying to find some time to tackle the RTC issue. I have just not had time.... One thing I did notice is the the R16 (capacitor?) which is next to the RTC chip, appears to maybe be compromised. It's hard to tell because these things are so damn tiny.
As I posted earlier, Oxiclean is mostly sodium percarbonate and to a lesser degree sodium carbonate, which when combine with water, the sodium percarbonate BREAKS DOWN INTO H202!with Lumpydog's technique working wonders with virtually no H202 at all (less than 1.5%, from what I see), I can't help but wonder if that OxiClean isn't doing most of the job on its own.
In other words, whatever percentage of H202 is already in your liquid solution, the "Oxy" product increases it along with the PH level. So you are being mislead by only looking at the H202 percentage lumpdog uses as the Oxiclean is upping it as well. However, since others are starting with a much higher H202 percentage as well as using an "Oxy" product, lumpydog's overall solution is lower in H202, but ultimately more than indicated on the bottle. As for "doing most of the work", I would think not. Since no matter how much Oxy compound you put in water, it still won't produce as much H202 as a mixture already containing it. Plus, there is a limit to how much powder can be absorbed by the water and possible negative effects from the substantially increased soda ash in using an Oxy compound alone.
Since you already have a source for the substance, this is something of a moot observation, but most of those in the Vintagecomputing forum achieved equally amazing results to lumpydog without specifically using Oxiclean, but a generic "Oxy" product. My guess is Oxiclean happened to be the brand lumpydog had on hand (which he may answer for us). While caution is prudent in the restoration of an irreplaceable Mac, I think Oxiclean is more marketing than "magic" (appearing on direct marketing infomercials and commercials frequently here in the US). According to its website, it uses the exact same ingredients as the brand I picked up at my local supermarket (which carried half-a-dozen varieties, none of which were Oxiclean). The use of a local variety might save you a fair amount over Oxiclean's inflated price, not to mention shipping to Japan.
Yup! What I had on hand :beige:My guess is Oxiclean happened to be the brand lumpydog had on hand (which he may answer for us).
Lumpy
C16 or R16? The C16 capacitor is the one right next to the CLK. The R16 resistor is next to the filter. C16 could definitely be a problem as it appears to be connected to the power pin -8- on the RTC chip. Since you know power from the battery is good to pin-11 on the logicboard, and your PRAM does not retain settings after restart, the backup power is likely not making it reliably into the RTC causing who knows what kind of problems. If so, it is definitely an easier fix than finding a new RTC. Could that capacitor have blown when you had the battery in backwards?One thing I did notice is the the R16 (capacitor?) which is next to the RTC chip, appears to maybe be compromised. It's hard to tell because these things are so damn tiny.
If your HD20 plastic & paper labels did OK, I'm sure the 512K labels will as well. I suspect the problem with the logos is that they are metal and are painted. H202 is highly corrosive to metal. That alone could account for the paint blistering due to the chemical reaction beneath it. However, the paint could be lead-based, or other susceptible base as well. Considering these as possible explanations for the damaged logo, I am actually surprised that the metal-based coating on the inside of the cases is left alone. Some aluminum is immune to H202's corrosive effects so perhaps that explains it. Anybody know the composition of the RF paint used inside the early Macs? What about the later metallic coatings in the SE?I'll let you know how the rear plastic label and the paper serial number label fair.
Mac128 - you're correct. It was C16.... NOT R16 - thanks for asking. I was at work.
I'll need to look more closely at it this weekend. it appears to be damaged - but it's hard to tell. No burn marks, etc.
I'll need to look more closely at it this weekend. it appears to be damaged - but it's hard to tell. No burn marks, etc.
Ok Mac128... My multimeter says C16 on the logic board is toast (it looks it too). Everything else that I tested around the RTC (including the battery checks out).
What is the replacement part number/description for C16 on the logic board? - it is a diode... Where can I get a replacement?
Pina, in his book, does not appear to give the detail to logic boards that he gives to the analog board.
I'm hoping you might be able to provide some help/direction on getting the part to replace C16...
Lumpy
What is the replacement part number/description for C16 on the logic board? - it is a diode... Where can I get a replacement?
Pina, in his book, does not appear to give the detail to logic boards that he gives to the analog board.
I'm hoping you might be able to provide some help/direction on getting the part to replace C16...
Lumpy
According to the BOMARC and Apple SE/30 schematics I have, the positive side of polarized capacitor C16 is connected to pin 6 of UB10 and UB11 (the Sony chips), and is also connected to R5 and R11. And the other side of R5 connects to the Reset switch. Both schematics show C16 as ".1" which I assume is 0.1uF (microFarad). C16 is found on the bottom of the logic board, nearest the two switches.
I have C16 shown in PDF form, in both schematics, hosted on Google Docs. Stupidly though, Google Docs won't let me share PDFs with everyone, so I have to manually plug in email addresses to give people individual access. PM me with your email address if you want to see my PDF.
Now with that said, I suspect your C16 may be just fine. You would likely need to remove it from the logic board to perform an accurate test anyway. C16 is a chip capacitor which, unlike the big tanks on the top side of the board, don't tend to fail over time.
I have C16 shown in PDF form, in both schematics, hosted on Google Docs. Stupidly though, Google Docs won't let me share PDFs with everyone, so I have to manually plug in email addresses to give people individual access. PM me with your email address if you want to see my PDF.
Now with that said, I suspect your C16 may be just fine. You would likely need to remove it from the logic board to perform an accurate test anyway. C16 is a chip capacitor which, unlike the big tanks on the top side of the board, don't tend to fail over time.