P4 401 module with corrosion, ideas for cleaning?

[spinchb]

Hi All,

I have a P4 module that is really corroded. I've tried to clean it up as best I can, but it's totally dead. I even replaced the QC. I'm ready for drastic action. The problem that I can see on the board is that the components below the display have corrosion on them still. Likely they are shorting out instead of doing their job. What can I use to dissolve that corrosion away? Is something like CLR too strong? Or, is there something better out there?

Thanks for the advice!

Best,
Shawn

[clockace]

try white vinegar, water, alcohol, dry w/warm air in that order. it has worked for me but not always. if the pulsar module is that corroded it is probably dead. maybe a new oscillator chip? see a few posts back on that. peter

[spinchb]

Hi,

I already tried alcohol, which helped quite a bit. I was thinking something acidic might help dissolve some of that crap on there.

When I place the voltmeter on various positions on the board, it seems as if it is counting. There are points where the voltage increases from 0 to 1-ish in 12 steps, and another where there are 4 steps. I think the QC is doing something. No display though, which would make sense if the transistors are all gummed up as they drive the display. I'm out of oscillators though, seems I should keep a bigger supply on hand. They get used up.

I'll try vinegar and a rinse in alcohol and see what happens.

Cheers,
Shawn