Washing a PCB... have you done it?

[Niku-Sama]

i am going through cleaning things and i finally tackled my greasy PSX

literally greasy. like it was hosed with cooking oil. it was every where except under the lid. i dont know how it happened, i just forgot about it and stuck it away and it sat.
its very funky because inside it rused the sheilding but the PCB had no corrosion on it. it also ate away at the lower half of the plastic shell. the top half is fine strange enough.
and by ate away i dont mean huge holes and stuff, the stand offs and alignment tabs are all crumbly, quite a few of them just turned to powedery goop.

any way i tried regular electronics cleaner and it wasnt cutting it so i figure if i leave it this bad and try turning it on its going to fry any way, so i washed it in the sink with dish soap and a brush.
super hot water so it will evaporate quicky.
before i went at it i tested it with a multi meter to check for any residual juice left over in the caps, hasnt been on in a very long time but caps hold a grudge for a very long time.

i had to clean all 3 PCBs in this thing this way, PSU, Main board, Controller board. i'll let you know how it works out when its dry.
did this once before and it was ok afterwards, some one puked into the front pannel of a PC i was rebuliding and its working fine
this on eht other hand i'm not so sure about, theres a bit more to it than usb ports and a card reader with a power button.



has any one ever had to come to this?

[Tokimemofan]

i am going through cleaning things and i finally tackled my greasy PSX

literally greasy. like it was hosed with cooking oil. it was every where except under the lid. i dont know how it happened, i just forgot about it and stuck it away and it sat.
its very funky because inside it rused the sheilding but the PCB had no corrosion on it. it also ate away at the lower half of the plastic shell. the top half is fine strange enough.
and by ate away i dont mean huge holes and stuff, the stand offs and alignment tabs are all crumbly, quite a few of them just turned to powedery goop.

any way i tried regular electronics cleaner and it wasnt cutting it so i figure if i leave it this bad and try turning it on its going to fry any way, so i washed it in the sink with dish soap and a brush.
super hot water so it will evaporate quicky.
before i went at it i tested it with a multi meter to check for any residual juice left over in the caps, hasnt been on in a very long time but caps hold a grudge for a very long time.

i had to clean all 3 PCBs in this thing this way, PSU, Main board, Controller board. i'll let you know how it works out when its dry.
did this once before and it was ok afterwards, some one puked into the front pannel of a PC i was rebuliding and its working fine
this on eht other hand i'm not so sure about, theres a bit more to it than usb ports and a card reader with a power button.



has any one ever had to come to this?

I do it to LCDs and grounding plates but be careful, on the circuit boards water can remain under the ICs so use compressed air to blow it out, and the connector for the laser MUST be dried by hand since they are extremely prone to corrosion.

[Compute]

We bake PCBs at 125 degrees C to be sure to get rid of residual moisture. If you can set your home oven that low, it should work. Just make sure it's ONLY the pcbs and there won't be anything to melt. Otherwise compressed air works well, too.

[FABombjoy]

I agree with the above posters. Washing is fine provided that you're aware of the water that will find its way under chips and into other parts. I rework a lot of boards with cap failure and washing is a must.

Tap water is OK provided that your municipal system is relatively good. If you have a well or you're not sure, use bottled or filtered water.

There are dedicated PCB cleaners. Dow Bathroom Cleaner works well, too. A soft, long nylon bristle paintbrush can help dislodge any stubborn contaminants.

If you decide to bake the water out, be sure to preheat the oven & turn it off before putting PCBs in. Otherwise, should the heating element kick back on, you can get hot spots and warp the PCB.

[Niku-Sama]

well i know all of that, the oven only goes to 200 but i just stick them on the heater vent for a few hours and it was fine.

plugged it in and turned it on, light comes on, cd spins and laser comes on. no smoke so thats good. dont know if it will play games though but i have a feeling it might be for parts any way.
i saw another one at the as-is store a while ago that was thrashed on top.

or, a portable maybe, its no big either way, its a scph 7501 if any one is wondering

[Graham Mitchell]

Ive got a pretty dirty pcb on the way that's definitely going to need some cleaning, so its opportune that this thread came up. I was just going to lightly wipe it with a damp towel. Is that fairly safe, as long as I make sure the board is dry?

[shadowkn55]

I would use a soft-bristled brush like the ones for polishing shoes to remove loose dirt particles from a board. I've have old boards layered with residual dust from storage and it did the trick. Make sure the board is dry before starting.

[jb143]

When I worked in the electronics industry, we would put PCB's in a standard dishwasher. No soap or jet dry or anything like that obviously. And these were for high end industrial controllers. So yeah, it's ok to clean with water so long as the boards are completely dry afterwards.

[Niku-Sama]

well at the same time about them being completely dry before turning them on you need to make sure theres completely no juice left in it any where weither it be in a capacitor, cmos battery or something of the sort. you can still fry some thing when its not plugged in all un hooked.

like i said before i tested the capacitors and many different points on the board to make sure it had nothing left in it.
also if this wasnt some for of cooking oil looking sort of stuff and just dust i would have used a short brissle paint brush and some compressed air with a blower attachment on it


Graham Mitchell post a pic of this board.

[Graham Mitchell]

well at the same time about them being completely dry before turning them on you need to make sure theres completely no juice left in it any where weither it be in a capacitor, cmos battery or something of the sort. you can still fry some thing when its not plugged in all un hooked.

like i said before i tested the capacitors and many different points on the board to make sure it had nothing left in it.
also if this wasnt some for of cooking oil looking sort of stuff and just dust i would have used a short brissle paint brush and some compressed air with a blower attachment on it


Graham Mitchell post a pic of this board.

It hasn't arrived yet, but here are the pics from the auction:

http://www.ebay.com/itm/200723771956?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2648#ht_500wt_1413

It's a Nintendo Vs. System PCB with a Vs. Super Mario Bros chipset installed. It was apparently in a box that got infiltrated with termites so it's full of what I suspect is termite shit. I ordered some PCB cleaner and compressed air from New Egg. I don't plan on submerging this in water or anything, but I do think it's going to take more than just shooting some compressed air on it. Do you think I could just spray it with the electronics cleaner, brush it off with a paintbrush (or I have a shoe brush!) and dry it with compressed air?

Edit: Oh, and testing caps--do I need a voltmeter or something for that? How do I discharge them if they're live?

Thanks, guys!

[bust3dstr8]

That thing is a mess I would pop the chips and put it in the dishwasher with a small amount of Simple Green. After it comes out you can use the compressed air to blow out the sockets and under the chips.
Let it dry for 48 hours, in front of a fan is nice if you have one handy.

Don't worry about the caps, they won't have any charge left in them.

[Graham Mitchell]

I know, it's a labor of love, I tell ya. This little arcade adventure has been a lot of work.

So should I just pour some simple green in the soap tray? Lower heat is probably better, too, right?

[CRTGAMER]

i washed it in the sink with dish soap and a brush.
super hot water so it will evaporate quicky.
before i went at it i tested it with a multi meter to check for any residual juice left over in the caps, hasnt been on in a very long time but caps hold a grudge for a very long time.

i had to clean all 3 PCBs in this thing this way, PSU, Main board, Controller board. i'll let you know how it works out when its dry.
did this once before and it was ok afterwards, some one puked into the front pannel of a PC i was rebuliding and its working fine
this on eht other hand i'm not so sure about, theres a bit more to it than usb ports and a card reader with a power button.



has any one ever had to come to this?

DO NOT IMMERSE YOUR PCB IN ANY LIQUID!
Especially water! You are sure to ruin a capacitor or two which are not water tight. any moisture that gets inside will be imposibble to dry out and just amplify the cathod to anode process. If the PCB is that caked with an oily film, just go easy on the board itself with alcohol and a small brush. Blow dry with a can of air.

[shadowkn55]

DO NOT IMMERSE YOUR PCB IN ANY LIQUID!
Especially water! You are sure to ruin a capacitor or two which are not water tight. any moisture that gets inside will be imposibble to dry out and just amplify the cathod to anode process. If the PCB is that caked with an oily film, just go easy on the board itself with alcohol and a small brush. Blow dry with a can of air.

You can disregard this statement. Many industry professionals have used the dishwasher rinse cycle to clean boards without problems. In fact, it was standard practice to do this at SNK USA, as stated by Nightmare_Tony, a former employee. As long as you you don't dunk the board is water for long periods of time and allow it to fully dry, there will be no damage to the board.

Capacitors are also sealed against liquids otherwise the electrolyte would leak out and render it useless among other things. If the cap is old enough to where water penetration is a concern, it's about time to have to recapped anyway.

[CRTGAMER]

You can disregard this statement. Many industry professionals have used the dishwasher rinse cycle to clean boards without problems. In fact, it was standard practice to do this at SNK USA, as stated by Nightmare_Tony, a former employee. As long as you you don't dunk the board is water for long periods of time and allow it to fully dry, there will be no damage to the board.

Capacitors are also sealed against liquids otherwise the electrolyte would leak out and render it useless among other things. If the cap is old enough to where water penetration is a concern, it's about time to have to recapped anyway.
You do know Capacitors are "dry cells" right?

[shadowkn55]

You do know Capacitors are "dry cells" right?

Only some. The most commonly used ones back then were standard electrolytic capacitors that were filled with a liquid called electrolyte.

[CRTGAMER]

Corrosion occurs when three things combine. Air or Oxygen - Metal - Moisture. The metal and air cannot be removed, so it is best to not introduce any water or water based cleaners. Stick with petroleum based cleaners to minimize the moisture. Dry components immediately after any cleaner is applied.

http://www.arwatson.com/images/corrosion-triangle-nomoisture.gif

Take a look at this exploded diagram of a capacitor and imagine any moisture or condensation seeping in.

http://www.digitivity.com/articles/capacitor-breakdown-thumb-404x615.jpg

[Shulamana]

You can't remove moisture from the equation either really, there's plenty of it in the air all the time unless you live in a literal desert.

Time is also a fourth factor here. A lot of moisture for a short amount of time (without the presence of electricity in the circuits) is not really much of an issue if it dries off quickly, but a very tiny amount of moisture over years, or even months can lead to rust.

[shadowkn55]

Take a look at this exploded diagram of a capacitor and imagine any moisture or condensation seeping in.


And where exactly are the holes large enough to allow water to enter? If water can enter the inner chambers so easily, then the opposite is true. The electrolyte would also be able to escape. Any loss in electrolytic fluid alters the capacitance rating of the cap. Why do you think people recap arcade monitors and turbo duos? The fluid has dried up and the capacitors can no longer hold a charge. Yes, there are microscopic holes in the material (nothing is non-porous) but rate of escape is measured in years, not the 20 minutes in a rinse cycle.

[alec006]

They're right, water isn't going to do anything to the board unless it's still wet somewhere. I've doused a board in CLR before because there was so much battery corrosion on the board that I had to scrub off. There were transistors, capacitors and many other electronic components on the board that got doused as well. I then rinsed it under hot tap water and let it dry in the garage in the Texas summer for 24 hours, and it fired right up no problems what so ever, that was half a year ago, I checked the board and there's no signs of rust or corrosion anywhere.

Now grated CLR is a different liquid entirely, but it's also a mix of corrosive acids so if a board can survive a mix of acids, then a neutral liquid like water won't do a damn thing to the board as long as the board is completely dry before any electricity is run through it.

[bust3dstr8]

Alec using CLR sounds like a great idea. I have been using vinegar to clean corroded pads,
but heavy corrosion I need to scrap them to expose fresh tin/copper.

I have a Laseractive pac I am working on with well over a hundred corroded pads.
If I dab each contact with some CLR how long should I let it sit?

[alec006]

Alec using CLR sounds like a great idea. I have been using vinegar to clean corroded pads,
but heavy corrosion I need to scrap them to expose fresh tin/copper.

I have a Laseractive pac I am working on with well over a hundred corroded pads.
If I dab each contact with some CLR how long should I let it sit?

If your gonna use CLR be sure to wear rubber gloves or not let it touch your skin, it will burn if left on your skin for too long.

I would dab a Q-Tip with some CLR and see how it reacts with the corrosion. If the corrosion is a strong base it will bubble up nicely then you could use an old tooth brush to scrub it off quickly.

The battery corrosion I cleaned off a board took about 2-3 times of pouring small dowsing amounts of CLR and lots of scrubbing before I got it all off. I then rinsed it off with hot tap water immediately afterwards and let it dry for 24 hours.

Depending on the temperature and humidity where ever your gonna let it dry lets you know how long you should leave it out for. When I let my board dry, the humidity was about 20% outside and it was 105 in the garage. To be on the safe side I'd let it dry over a weekend, or 48-72 hours if it's cold or very humid.

[Tokimemofan]

You could also use ammonia instead, that is also pretty good for corrosion, though any decent acid or base should work.

[bust3dstr8]

The CLR worked great. I dabbed a little bit on the pads with a q-tip and let sit for about 20 minutes. The pads took the new tin real well and should be real easy to solder new caps to.

[alec006]

The CLR worked great. I dabbed a little bit on the pads with a q-tip and let sit for about 20 minutes. The pads took the new tin real well and should be real easy to solder new caps to.

That's wonderful to hear, I'll keep that in mind when I do contacts :)

[ciciswift]

re: (http://pcb.hqew.net/?s=544864)It's not PCB's bussiness!but i searched this

[Niku-Sama]

huh?

that PlayStation works fine by the way.
tossed the shell because it crumbled apart, used the mobo to replace a fried one. still going, gave it to a friend of mine.

[channelmaniac]

It's an old thread, but I've washed HUNDREDS of boards and other items such as keyboards over the years...

I cleaned a few Neo Geo game boards in the sink over the past 2 weeks with liquid dish soap and a tooth brush. Got the gunk out of the slots nicely and cleaned up the boards very well. They went into the oven at 170F for 30 mins each and they came out toasty and dry.

I've NEVER had a board sent back for repair that was ever damaged by cleaning in this way.

RJ

[ApolloBoy]

Wouldn't that leave behind water deposits which could potentially damage parts of the board?

[Graham Mitchell]

Wouldn't that leave behind water deposits which could potentially damage parts of the board?

Yes that's why they're recommending blowing the board out with compressed air and mildly heating to evaporate stray condensation.

[channelmaniac]

I don't have hard water where I live and thus have no concerns about mineral deposits. Drying in the oven at 170F quickly gets rid of all the water, will not damage caps, and keeps the water from being on there long enough to cause rusting/corrosion issues.

Manufacturers do waterbaths for new production PC boards, but they used de-mineralized and de-ionized water.

[McFlY88DmC]

I've done it once myself before. I was doing a full capacitor replacement on my Model 1 SegaCD, and the seller I bought the replacement caps from said to carefully scrub the board with bathroom cleaner in order to remove the corrosive electrolyte that had leaked out all over the board. I was scared as heck to do that initially, but it wasn't that big of a deal in the end. I did rinse the board in distilled water, since my tap water tends to leave crusty mineral deposits all over things. I also used compressed air to blow out some of the residual water under the chips/sockets. Be sure to let things dry out for at least a day or two.

That SegaCD has not given me any grief since I finished the repairs over six months ago. YMMV of course :)