Techy question about cleaning PCBs

[D-Lew]

Didn't know where else to put this, but... Surely someone here has done it.

I need to know how, because I believe the gauge cluster PCB in my car is corroded, causing it to act all funky according to similar incidents all over the internet. 

So I need something to clean up the rust.  Someone said spray it down with WD-40 but that sounds weird, and I don't have any on me right now.  I would rather not go get some if it's not going to do any good.  Any home remedies for an issue like this?  Thanks guys.

[SirPeale]

WD-40 might prevent it from continuing to oxidize, but you have damage that needs to be repaired.

You'll have to clean the circuit traces and run jumper wires over the split sections.  You'll have to solder them in.

Then I'd suggest sealing the board somehow (AFTER testing, of course) to prevent further oxidation.

[D-Lew]

Hmm... not exactly what I wanted to hear but useful info nonetheless.  I don't think it will be bad since the car is fairly new, but I think it's causing issues with grounding.  Hopefully it's just mildly dirty.  Thank you.

[SirPeale]

Without seeing the board it's difficult for me to diagnose.  Best I can do based on your description!

[D-Lew]

Yeah I understand.  I tore it down the other day looking for loose wires or shorts but turned up nothing... now I have to pull the assembly back out and gut it down even further to the PCB to be able to tell what's going on in there.  I might be back with pictures if I need them, but at this point I'm about ready to just start buying new parts.  Wish me luck... 

[Hockeyboy]

If it's a PCB board that has components on one side and solder runs on the other you can use Isopropyl Alcohol (rubbing alcohol) and some q-tips to remove almost all of the corrosion or gunk that is on the board without ruining anything, honest. Then, after you have it cleaned off you need to examine the connections, solder runs, etc and see if they are still intact. You can then solder in some jumper wires as mentioned, but the caveat is that if you don't know the current running through that board and put in wires that are too thick or thin you could cause some serious damage and even start a fire!

If the car is fairly new, take it to the dealer, tell them you were look at stuff and you found this problem and let them replace it.

[D-Lew]

It's out of warranty.  I do all my repairs that are within my skills myself and have probably saved around $1000-1500 doing so with minimal service...  besides if I ruin this gauge and have to buy a new one anyway, no harm done because I would get ripped for that $300 plus labor anyway.  I'm going to try to get it done this weekend, along with inspection and cleaning of every single ground in the car that I can get my hands on.  AFAIK it is one sided and it's only the back I'm concerned about.  The front just has lights, servos, and some kind of IC/BIOS, don't know exactly what to call it, that contains the mileage (yikes!).  What I find hilarious is how easy mileage fraud would be on this thing.  Simply swap out the cluster with a wrecked car that had less miles on it. 

But I am an honest man, so I'm not going there... and/or prison.

[ark_ader]

Didn't know where else to put this, but... Surely someone here has done it.

I need to know how, because I believe the gauge cluster PCB in my car is corroded, causing it to act all funky according to similar incidents all over the internet. 

So I need something to clean up the rust.  Someone said spray it down with WD-40 but that sounds weird, and I don't have any on me right now.  I would rather not go get some if it's not going to do any good.  Any home remedies for an issue like this?  Thanks guys.

Get a small steel brush and give it a good scrub.   

[danny_galaga]

but the caveat is that if you don't know the current running through that board and put in wires that are too thick or thin you could cause some serious damage and even start a fire!

you can't cause damage by putting in a wire that's too thick. more current won't flow because of that! obviously if it's so thick you risk shorting several runs together then that's not good. too thin would be a problem, but it's not hard to gauge from the size of the track and from wires that might be attached nearby (there is obviously no need for wire bigger than exists going to the pcb)

[Hockeyboy]

Very true, DG...if you get wire that is very close to the same size then current flow and excessive heat most likely won't be a problem. I was simply trying to be conservative and safety-conscious. 

Hope it all worked out for D-Lew though? No word yet??

[D-Lew]

I've talked to a car buddy and am trying to sort out my options before I dive into this.  So I'm still driving around and half the time not knowing how fast I'm going.

Apparently there's "electrical cleaner" (go figure!) so I'm going to get a hold of that and give it a try, spray the hell out of the board and see what happens.  It's just a matter of me finding time to tear down that dash again.

I don't frequent this forum as much as I did before but I appreciate all the input guys.  I'll drop back in once I get it fixed, one way or another.