Recent finds... one Classic from Free Geek Minneapolis for $10, listed as "No HDD, bad analog board," second one from Craigs List listed as "battary bomb" for $5 (their spelling).

What I spares have on hand: A working system (Classic motherboard and Classic II analog board from an old Hackintosh conversion before I was a collector), and a scrap frame and analog board I found where someone had clipped lots of the wires (with a homebrew transparent case not completed). The tube was damaged (tip broken and gas vented) and I used it to melt my plexiglass cover for the Hackintosh conversion.


This will be an attempt at a "quick fix" to get both working with the spares I have on hand, basically rendering my spares as projects for a full recap and restoration in the future. I can put my working analog board into the bad one. I can put my good frame and motherboard into the battery bombed one.

Step 1: disassembly and damage assessment

Battery bombed was indeed crusty. I could not remove the motherboard so that will have to soak in vinegar for some time. I could not remove the motherboard without fear of damage, so I removed the whole frame from the case (tricky to get those 4 screws when you can't remove the floppy or motherboard).





Bad analog board: Yep, that got some crusty goo as well, but easily repairable frame. I won't delve into the recap yet.


More updates will come after some cleaning and electrical testing.

One of my first Mac purchases after getting back into the hobby was a Classic from a nice lady in Minneapolis. I don't think I paid much for it, but had I taken the time to shake it first... well, I should have paid less! I was able to eventually restore the entire thing to working shape, but I won't say it was a simple recap job like I expected. Lesson learned!

I was able to clean up the bad analog board bottom frame, hit it with a wire wheel and spray painted it. Don't mind the paint runs, you won't see it inside.


It looks like I have 3 bad analog boards, so I am ordering recap kits for two of them. I just don't have all the capacitor values on hand. I still have 3 good tubes (assumed), 3 good frames, 2 working logic boards, two good cases... So this battery bomb one will take some work, but I think it is recoverable, and maybe that will go into my homebrew transparent case.

This bombed logic board popped 3 caps on its own, but I should be able to clean up and mend the traces or at least bodge them if needed. RTC legs need some help as well as the sound chip.

Having too many disassembled parts laying around, so I just put the working parts into the better case (marked bad analog board), so I have less clutter.

I put in an older BlueSCSI 1.1 and I wanted to see the activity/power lights without modifying the case. Cheap and easy way was to use a twisty-tie on the back vent.

So if it's backed into a dark corner, you should see the reflection on the wall.

And a couple of tubes sitting on the shelf until I receive my cap kits for the analog boards.

I found a loose sticker inside the battery bombed case, so I taped it onto the case, not knowing what it was. Maybe cost of repair?

And then I saw a similar tag on the "bad analog board" tube... so maybe the battery bombed one had a tube replaced or serviced at some point.

Looks like that one says 203.18

makes me wish there was a Free Geek in my state. I did find a 637CD Money Magazine at an ewaste facility a few towns away from me. Anyone willing to donate a full 68040?

I received my two analog board cap kits from Console 5 a while ago, but I have been buried in other projects. Finally had the time to dig into the Battery Bombed analog board. The backside was quite goopy.

Then I removed all the caps. Not sure if I lifted that pad or it was too far gone (what is that black etching, do I have to remove it?).

It was definitely leaking most caps, but in particular around that etched part.

Liberal amounts of IPA and a toothbrush to clean it up as best I could. Let it hang dry for an hour. Soldered in new caps. Used the cap leg to bridge the lifted pad.

Reassembled the frame and guts, and hoped for the best.

I guess it was good enough! Image is rock solid but I may have to adjust the vertical size a bit. This motherboard is one I previously recapped, so I still need to go back and see if I can rescue the battery bombed motherboard.

So I now have two fully working Classics and some spare parts that I might still be able to get working (without a case). Or maybe in a homebrew transparent case one day.

wow, that took a while no doubt! always a joy when they finally do boot up!

From the three bad analog boards I had, two were 630-0395 and one was 630-0525 (other components missing or damaged). I ordered two cap kits from Console5, one for each type of board. The first 0395 board I recapped worked great. Then after looking at all the damage on the 0525, I decided I would try to fix the other 0395, but I had an 0525 cap kit. I found all but one extra caps from other component kits I had.

I then pulled two caps from an old power supply to run in parallel to replace the missing cap I did not have.

Soldered and hot glued the ends to cover the soldering as to not short anything out.

Reassembled the transparent hack case and no power.

Ordered the correct cap (still waiting for delivery), replaced the two diodes (DP3 and DP4), ordered TDA4605, IRFBC40, and CNY17G. Received TDA4605 and installed. Reassembled. Now it powers on, although very wavy. I assume once I replace the correct missing cap, and two other components it may solidify the image. This is the battery bombed motherboard that I am still working on.

I pulled the CNY17G from this board 630-0395 (left) and the one from the damaged 630-0525 board (right). They are different versions.

Installed the CNY75GB into the 0395 board, and now I get a solid image.

Now I have to concentrate on the battery bombed motherboard. After using the dental tool to remove most crud, and IPA cleaning, a little scratching with a blade and cleaning out some crusted VIAs with a micro drill bit, this is the results. Burn-in pads 1 and 2 completely gone.

A little back lighting to see what I can see for the VIAs. I still need to clean out the old battery terminal.

And from the bottom, R88, R89, R90 clearly corroded away.

Illuminated.

So I will start with the schematics and start tracing for some bodge time.

I removed the R88-R90 and saw the VIAs were completely gone.

I did not have any donor boards that had the correct size SMDs, so I used conventional through hole. Using the other leg on the top to join into existing traces. Same with some bodge wires from bottom to top.

Lots of the VIAs had just enough corrosion to miss the trace, so I dabbed on wire and snipped off at the VIA. Ugly and messy. After a few hours of pinging traces, I thought I got most of it.

Tried a power on test, and I had a modified checkerboard. So back to testing more...

I found four or five more bad traces and repaired them. Powered on again and I got the regular checkerboard and after a few seconds a chime and a gray screen, but no cursor. Pressing the reset button gave me the checker and the gray screen again.

I powered off, connected the floppy to see if it would seek, and then rolled video just in case it was success. Totally different outcome. Tried a little impact maintenance. I then got checkerboard and scrambled checkerboard... resets gave me different outcomes, scrambled audio, different scrambled video. So I am guessing there are a few more VIAs that need rework, probably have some corrosion inside, and possibly some cold solder joints somewhere.

Time for a classic Reloaded? ;)

wow, so cool! you figured it out now, good to know ! that board looks pretty sad, so much damage. even the solder paste turns to cement under those conditions. reflowing will be needed all round, and resistor values can also change under these conditions. hope you can get it cleaned up and run well !!