A Tale of Two Classics

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.

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

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.

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.