Just purchased Mac 512k

[lumpydog]

Of course, complete immersion of an entire classic Mac case is not practical for many of us

I've been so impressed by the non-damaging cleaning effect of this process that I am going to do my Mac 512K's case as well - it is slightly darker on the left side - something that is now noticable as it sits on top of the very nice/clean beige HD20.

I have a large clear tub - I'm going to try it next weekend. I will be seriously cutting the peroxide percentage to get enough liquid to fill the tub. We'll see how it goes (how low can you go!?)

One other observation - I left my keyboard case in the solution last night. I had been putting these items outdoors to get UV light. It was late, so I put the keyboard in my basement under a UV bulb..... and shut off the lights (and the UV bulb) on my way out of the basement - duh. I forgot that the master light switch cuts all ceiling lights/outlets in my basement. Despite the fact that the keyboard was in the solution - with the absence of UV light, it stayed the same. The yellowing did not budge or fade. So - on the way to work this morning I left it in my driveway - should be clean by the time I get home.

 

[Charlieman]

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?

It's the homeopathic approach, I guess ;-)

 

[Charlieman]

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.

 

[equill]

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

 

[JDW]

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.)

 

[Mac128]

2) coat the ABS plastic with UV-opaque clear finish, and to keep the cases away from heat and further UV-irradiation

Yes that raises an interesting point. As does JDW.

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.

 

[lumpydog]

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.

 

[Mac128]

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.

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).

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.

 

[lumpydog]

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.

 

[JDW]

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.

 

[Mac128]

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 still don't quite follow the flexing issue, but so long as it works now.

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.

 

[lumpydog]

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.

JDW - excellent 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?

 

[JDW]

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!

 

[Mac128]

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.

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.

 

[prd]

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.

I wouldn't take it personally, it's only been 8 days. :beige:

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.

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.

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.

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

 

[Mac128]

If I get around to this before the thread winds up, I can post some details and comparisons here.

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).

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.

 

[lumpydog]

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.

 

[Charlieman]

Real Time Clock failures in other models have been discussed here previously (use the search). This sounds like RTC to me.

 

[lumpydog]

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

 

[Mac128]

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.

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.

I take it the RTC is prone to failure in old Macs? If so, are there replacement options aside from cannibalizing old boards?