Baby Pac-Man MPU Board ... What to do?

kentmurphy

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Checkout the pictures of the MPU board in my Baby Pac. The board has a significant amount of battery acid corrosion, but the game works fine.

https://skydrive.live.com/#cid=4127EA3A33B50049&id=4127EA3A33B50049!3761
https://skydrive.live.com/#cid=4127EA3A33B50049&id=4127EA3A33B50049!3762
https://skydrive.live.com/#cid=4127EA3A33B50049&id=4127EA3A33B50049!3763
https://skydrive.live.com/#cid=4127EA3A33B50049&id=4127EA3A33B50049!3764

I've considered leaving the board as is, but based on everything I've read that's probably not a good idea. What say you? Should I attempt to remove the corrosion? The last time I did this to a board the results were not good.

http://techniek.flipperwinkel.nl/ballyss/rep/index1.htm#battery
http://www.noiselandarcade.net/index.php/2008/01/17/baby-pac-mpu-board-cleanup/

I've considered just buying the repair kit from Great Plains Electronics. The MPU board in a Baby Pac is -133 while this kit is for a -35 board. After reviewing the part list, I am fairly confident this kit will work. Can anybody confirm?

http://www.greatplainselectronics.com/proddetail.asp?prod=BALLY35-BA-KIT

BTW - There is a minor problem with the high scores being scrambled (see pic), but according to a post I found on tomshardware.com this is the result of the battery not being installed. I am certain this is correct because the high scores are retained if the game is turned on a few seconds after being turned off.

http://www.tomshardware.com/forum/59618-13-tech-bally-problem
https://skydrive.live.com/#cid=4127EA3A33B50049&id=4127EA3A33B50049!3765

Thanks
 
To be honest, yours is not too bad. The kit will have a bunch of replacement parts, but since yours works... you don't really need any of them.

Here's what I would do. Take the board out, and pour vinegar all over the bottom part of the board. Anywhere there's corrosion. Take a toothbrush, and scrub it until you get that vinegar all over it and get all of the alkaline corrosion off. Try to get it as clean as you can. After you do, rinse it off with water.

After you get all the vinegar off with water, pour rubbing alcohol all over it. The alcohol will wick up the water and help it dry off quicker.

Let it sit for a day or so to make sure all the water evaporates. Then plug it back into your machine.

The reason you can't just leave it is, the alkaline will continue to eat the board, even without the battery. Once you pour that vinegar on the alkaline, it will neutralize it. Alkaline is a base, Vinegar is an acid.

If you do order the kit, though, all the parts are the same. The only difference between a '-35 and a -133 is that the baby pac board has a diode installed in 1 place instead of a resistor.
 
Assuming you're fixing damage done by alkaline batteries (not acid based batteries) then any household acid is legit. White Vinegar or lemon juice concentrate and a vigorous scrubbing should do the trick. You may need more than one pass. Dry thoroughly. Do not use baking soda unless you are dealing with acid based batteries.
Mind the KOH (potassium hydroxide) as this is gnarly stuff--wear gloves keep pets away etc.
 
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