Safest way to clean a PCB?

Kaervak

Diamond Member
Jul 18, 2001
8,460
2
81
I came across a NES that's been sitting in a garage since the tail end of the cold war and it was rather filthy. I've cleaned everything except the PCB/electronics. The PCB isn't anywhere near as bad as the casing was, but it does need some work. Not a light cleaning, but a good amount of scrubbing to get all the garage funk off of it. What would be the safest way to clean it without damaging it? I do want the NES to be playable after it's cleaned. So would Clorox Cleanup be too damaging to it? Naturally after getting it clean I'd let it sit for a few days before plugging it in and trying it just be sure it's absolutely dry. Thanks all.
 

VirtualLarry

No Lifer
Aug 25, 2001
56,570
10,202
126
what about some toothpaste, and a "soft bristle" toothbrush? I think I still have some of those old "cleaning kit" things somewhere, but those were mostly just a foam pad of a certain shape/size, and some IPA. I recommend against ammonia or bleach, they can cause caustic reactions that can eat away at some of the smaller traces on the board. I've seen it.

 

Oyeve

Lifer
Oct 18, 1999
22,043
875
126
I once found my old Atari 800XL computer in the garage after being there for years. I took it apart carefully and soaked the boards in warm water with Dawn dishwashing soap for several hours, rinsed it all completely, let it air dry for a few days, put it back together and it was as good as new. I have also done this with mobos, cpus with took much AS paste and never broke anything. Just make sure you give it ample drying time. I even did this with a portable cd player that fell into a vat of oil! Dawn cleans everything off if you soak it for a while and rinse properly.
 

Jeff7

Lifer
Jan 4, 2001
41,596
19
81
I'll also vote for isopropyl rubbing alcohol. Just for the hell of it, I soaked an ISA sound card in rubbing alcohol for a week. It still worked afterwards.
 

Matthias99

Diamond Member
Oct 7, 2003
8,808
0
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Originally posted by: VirtualLarry
what about some toothpaste, and a "soft bristle" toothbrush? I think I still have some of those old "cleaning kit" things somewhere, but those were mostly just a foam pad of a certain shape/size, and some IPA. I recommend against ammonia or bleach, they can cause caustic reactions that can eat away at some of the smaller traces on the board. I've seen it.

Toothbrush = good for scrubbing -- with isopropyl alcohol. Toothpaste is a really, really bad idea (good for polishing metal, bad for cleaning circuit boards). It's probably not conductive -- but it'll leave residue and caked-on crap all over your PCB. You'd need to, at the very least, scrub it again with alcohol to get it clean.

If alcohol isn't doing the trick, you might try acetone (usually sold as nail polish remover -- but if you use random 'nail polish remover', make sure it's got nothing but acetone in it!). Just be careful, as it will melt plastics (like, say, a toothbrush) and will loosen epoxy (and so could separate glued-on heatsinks, etc. from a PCB).

Whatever you use (soap+water with thorough rinse, 99% isopropyl alcohol, acetone), make sure you let the board dry *completely*. Alcohol and acetone evaporate quite rapidly, but you'd want to let something you'd cleaned with water sit overnight.
 

bigpow

Platinum Member
Dec 10, 2000
2,372
2
81
blow duster should do the trick


I'd avoid using any alcohol or solvent, definitely no-no with toothpaste, Brushes, etc.
 

Matthias99

Diamond Member
Oct 7, 2003
8,808
0
0
Originally posted by: bigpow
blow duster should do the trick

This won't help if there is actually dirt or grime on the board (not just dust).

I'd avoid using any alcohol or solvent, definitely no-no with toothpaste, Brushes, etc.

Alcohol and acetone are nonreactive and evaporate away cleanly, and are perfectly safe for use on circuit boards. A soft brush will not damage anything -- but you certainly don't want to use a wire brush, or steel wool or anything like that!

 

Mark R

Diamond Member
Oct 9, 1999
8,513
16
81
1st thing, make sure there are no batteries, or unsealed switches, or other mechanical parts, on the board.

If that's OK, then you can clean it pretty much however you want. I'd wash it in warm water with a little mild detergent - scrub gently with a medium bristle brush like a toothbrush, or fingernail brush.

When you're finished washing it, rinse thoroughly with distilled water (if you have a good quality water filter, then you could use filtered water).

Allow to air dry before use - best to leave in an airing cupboard or similar. Note that it may take several days, even a week, for water trapped under the chips to dry.

If you're really lazy, you could just chuck it in the dishwasher - i've done this for smll homemade PCBs to clean them up after soldering, but don't know what a domestic dishwasher will do to a complex PCB. So no guarantees with this technique.
 

Jeff7

Lifer
Jan 4, 2001
41,596
19
81
Originally posted by: Mark R
1st thing, make sure there are no batteries, or unsealed switches, or other mechanical parts, on the board.

If that's OK, then you can clean it pretty much however you want. I'd wash it in warm water with a little mild detergent - scrub gently with a medium bristle brush like a toothbrush, or fingernail brush.

When you're finished washing it, rinse thoroughly with distilled water (if you have a good quality water filter, then you could use filtered water).

Allow to air dry before use - best to leave in an airing cupboard or similar. Note that it may take several days, even a week, for water trapped under the chips to dry.

If you're really lazy, you could just chuck it in the dishwasher - i've done this for smll homemade PCBs to clean them up after soldering, but don't know what a domestic dishwasher will do to a complex PCB. So no guarantees with this technique.

My worry with a dishwasher is that it might blast components right off the circuit board.