POP! Goes the capacitor...

bridgeda

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I ended up with a pinball machine over the weekend that worked ok. It had a few gremlins that needed to be evicted but I have yet to own a machine that wasn't a little rough around the edges when I first invited it into my collection. I ripped the play field apart cleaned with Q-tips and a toothbrush every nook, put new rubbers on, installed new LED bulbs, and fired her up. I still had lights out so I pop open the top box and to my horror find the culprit.

A long time ago in an arcade far, far away... The 100uf cap on the driver board blew and spewed its nasty filling all over the driver board. Judging from the level of corrosion this probably happened years ago and was never addressed. It burned a hole through the board itself trashed a resister, a smaller cap, and three trace leads.

I can replace the caps and resister, retrace the board, and fix the transistors that were definatly destroyed. That is no problem. But there is a lot of corrosion here and there on the board which is most certainly going to cause me trouble in the future. Any words of wisdom on how to get the corrosion under control once the board is correctly repaired?

Thanks!
 
What game is it? Any pictures of the damage?

Vinegar is only going to work with corrosion caused by nickel cadmium batteries. If what damaged your board was electrolyte from a capacitor it will take something like baking soda to neutralize it.
 
A spray can of solder "Flux Remover" works well along with a scrubbing with a toothbrush as it's being applied.

Flux remover should clean that right up.
 
Its a gottlieb Super Mario Bros. Machine seriously needed a new home and a Hug. I just this evening replaced the last of 14 CPU controlled lighting diodes...

What a pain!
 
I would probably just scrub that off with alcohol and a tooth brush or flux remover as Ken suggested. To me it looks like one of the smaller caps or a resistor fried. Not the electrolytic. I would also want to be sure there's not a shorted transistor or something that caused that component to burn. It's kind of hard to tell from the picture so I could be wrong but something definitely burned. To me the black stuff looks like smoke damage, not corrosion.
 
about half of the top of the transistors are coated with a nice soft green bit of corrosion. I scrubbed the board down and am waiting on the replacement components. I had two transistors test "suspect" so they are going to get replaced along with the items damaged by the "blast" as soon as they arrive. What is most strange about this is the board still works...
 
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