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Leaky battery on a Macintosh Classic motherboard

Hello 68kMLA!

This is my first time posting in any kind of forum (unless you count Reddit), so please let me know if I'm doing anything wrong.

I recently bought a Macintosh Classic for about $60 on eBay, and wanted to try and get it up and running. This is also one of my first times trying anything out like this, the only other experience I have is buying an IBM Model M No.1391401 and restoring it to working condition. I took out the motherboard hoping that only the capacitors were causing the problem, after reading that it's one of the most common problems, but I was met with a bigger problem, as the title of this post suggests. 

20180418_200405.jpgtry.jpg

The battery holder is supposed to be there, but it seems that the battery acid corroded the area around it, causing the battery holder to fall out as well. The metal pins that are supposed to stick out from the holder is stuck inside the board, and a small capacitor that belongs to the Y1 slot near the corroded area has fallen off as well.

20180418_200857.jpg20180418_200910.jpgback.jpg

I guess the advice I'm looking for is what's the best course of action to get this Classic working, if at all? Is it worth to try and get this motherboard fixed, or should I try and look for a new motherboard? Or perhaps am I overlooking other problems that may exist in the computer?

 
Start with cleaning up the remaining battery goo and visually inspect the traces underneath.

Even if there are a few broken ones this is totally fixable. I have seen way worse battery damage that has been fixed.

The crystal at Y1 that fell off is needed for the real time clock. You can leave it out for now.

You will still have to replace the capacitors. You might also want to touch up all corroded solder spots inthr battery area.

 
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I had success with white vinegar to clean up the board of my SE/30, although it was a lot less worse

 
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This one is definitely fixable. You are actually very lucky that Maxell didn’t leak all over the place. One of my SEs got damaged by a Maxell, still haven’t come round fixing it but it’s got far more damage than your board and yet I’m sure it is doable.

White vinegar is great to remove/neutralise rust. Soak the board, get an old toothbrush and start scrubbing.

 
This is my first time posting in any kind of forum (unless you count Reddit), so please let me know if I'm doing anything wrong.

I recently bought a Macintosh Classic for about $60 on eBay, and wanted to try and get it up and running.
Buying a broken old computer for $60?! Ooff...

Well, let's get this fixed. Vinegar as suggested earlier is a good solution. Here's another suggestion: you can put the motherboard in your dishwasher. Arrange the motherboard so it's flat over the sprayer, parallel with the top and bottom of the machine. Splash in some vinegar from the bottle and set the dishwasher going. Do not use any soap. Only vinegar. You probably don't need to wait for the entire wash cycle, but only the first 10 minutes.

 
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Thanks for the replies everyone!

I tried a little bit of isopropyl with q-tips last night for general cleaning, but i'll definitely try some white vinegar when I have the time.

EDIT: Just did a quick search and it seems that many people advise not using vinegar to clean and instead to use isopropyl. Would continuing to only use isopropyl be okay?

@Bolle I don't think I see any traces damaged on the back, but here's a picture of the back if it helps at all (if a better picture is needed, let me know)

20180419_160942.jpg

Some quick extra questions: Any suggestions where I can buy new capacitors? Also, is a Macintosh Plus with original keyboard, mouse, Kensington system saver and Image Writer II Printer worth purchasing for $100?

 
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In my experience, the only board that will survive a battery leak is a Classic board. Here's what you do:

1. De-solder the what's left of the battery holder

2. De-solder all can style caps

3. Clean the area around the battery holder with rubbing alcohol and a tooth brush

4. Apply flux and re-tin ANY corroded solder joints

5. Place the board in the dishwasher without soap

6. Blow out all the ports with compressed air

7. Bake in your over at 170 Fahrenheit for 3 hours

8. Hook it up and see if it will boot

If it works you can then recap it and you should have a good solid board!

Classic and Classic II boards don't need ANY of those can caps to boot but without them you won't have any sound.

Here's replacement parts:

https://www.ebay.com/sch/i.html?_sacat=0&_nkw=32.768khz+crystal&_frs=1

https://www.ebay.com/sch/i.html?_odkw=1%2F2+aa+holder&_osacat=0&_from=R40&_trksid=m570.l1313&_nkw=1%2F2+aa+holder&_sacat=0

Good Luck,

Josh

 
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