Recovering Moldy Electronics?

cookiej writes "We just completed having our basement gutted and our house decontaminated from mold. The finished basement is gone, my office floor has been removed as well as 24' of drywall around the base of the room. So, we had a full home theater downstairs along with a couple of computers in the electronics closet that were completely immersed (rainwater, not sewage). We moved them to a sheltered area outside and covered them with a plastic tarp. Since the electronics were off when the water hit them, 1) do I have a chance of recovering them? 2) If so, is there a way to clean them with some sort of liquid bath that would not damage the electronics? and 3) I don't want to bring moldy pieces back in the clean house. How could I decontaminate the electronics themselves, pre-bath? Not looking to save the speakers, just the amp, DirecTV box, video switch, etc. Thanks for any help, here, Slashdot." Read on for more details of this reader's plight.
Early last month, we had about 10" of rain in the course of two hours. Many houses in our neighborhood were damaged. We had rainwater coming in our back door and cascading down the basement steps. We have two sump pumps that weren't keeping up (and of course, no battery backup) and as the water rose in the basement, it was getting dangerously close to the breaker panel. So I made the hard decision to shut down the main power and we got the hell out.

The water reached about 6' in the basement before it drained out. Once we got back, we could not move fast enough to get all the debris out before mold set in and boy did it.

Since we are not in a flood plain, our insurance for this is woefully inadequate. While I would love to just go out and buy replacements, there are far more pressing things to re-buy (washer/dryer, furnace, water heater, etc.) and if there is a chance I can salvage some of this it might be a nice change of luck.

Comments

There is hope

[dreamchaser]

If they were not plugged in they can be dried out and probably used again. I've never seen mold growing on electronics, but if you have mold/mildew you can wash them with a mild bleach/water solution. After they are clean flush them with distilled water and let them dry completely.

Re:There is hope

[mrbene]

"Completely" is the key phrase. Damage to electronics due to water is actually due to unexpected circuits forming and burning out components.

So if it looks dry, wait another couple of days.

Re:There is hope

[Anonymous Coward]

Bleach (chlorine) is a very bad idea. It will oxidize the metals very badly. Chlorine is incredibly corrosive.

Better to use a pure non-oil based solvent such as denatured alcohol (pure alcohol). Remember, nothing oil based like acetone or gasoline. Rubbing alcohol contains a lot of water so it's not best either.

Re:There is hope

[mea_culpa]

I use MG Chemicals Super Wash Cat# 406B-425G for cleaning most PCBs. The important thing to consider is if the electronics are new enough and worth saving it probably as BGA components that water will lurk under for weeks. This chemical can has 3 power settings and setting it to HI with the straw will push the residual water out. I have recovered many water soaked laptops using this and failing to get under the BGAs will lead to failure later on.

$15 per can at your local Fry's

Re:There is hope

[Anonymous Coward]

This chemical can has cheezburger

There, fixed that for you.

Re:There is hope

[capnkr]

Let me add to these other ideas a product named "Corrosion Block" (for the marine industry) and/or "ACF 50" (for aviation). Despite the different names, the product itself is the exact same thing, and works wonders on electronics that have been, or will be getting, wet. You can find it in most boating stores. Spray on a thin film, clean the electronics, let them dry thoroughly. A little goes a long way. The only caveat is that due to its ability/nature to "creep" over time (a good thing, it ensures even coverage), you want to use it sparingly around LCD displays so that it doesn't get inside. Living on a boat, I have had plenty of opportunity (too much!) to do what it is that you are having to do. :) Good luck!

Re:There is hope

[pushing-robot]

How the hell does water get *under* a BGA? The surface tension should keep it out.
The gap is tiny. Fractions of a millimeter.

How the hell does water get *into* a sponge? The surface tension should keep it out. The holes are tiny. Fractions of a millimeter.

Re:There is hope

[capnkr]

Oops, should have included a link:

http://www.nocorrosion.com/corrosion-control.htm

Re:There is hope

[plover]

No! Bleach BAD. Bleach will oxidize all the metals, including the ones you thought couldn't rust!

I have washed boards in the dishwasher before (no soap!) but that was for spilled liquids. With the presence of mold, you have a different problem.

First, remove any batteries on the board (coin batteries are common,) as they create a sparking hazard. Use pure isopropyl alcohol (not the 66% stuff) which will mix with remaining water and should help you both clean up and kill the mold. I'd start working over an empty pan, and pour alcohol over it as I cleaned it. Brush everything possible with a natural fiber brush (not a plastic bristled brush that may dissolve.) Get under components with a pipe cleaner. And no smoking around the alcohol, of course! When it's done, drain it. If you have access to it, thoroughly blow it dry with dried compressed air (air from an ordinary shop compressor will contain water and/or oil.)

Once the visible alcohol is gone, you'll still need to dry the board. It will take time, warmth, and air movement. An oven at the "keep warm" setting (no more than 170 degrees) shouldn't damage the plastics, but not while it's still evaporating alcohol fumes. A fan and some incandescent light bulbs (desk lamps up close) would probably do just as good. Warm sunshine is very good, too (and helps kill mold) but the humidity outside is usually pretty variable, so you wouldn't want it to remain outside in the evening to collect dew.

However, be prepared for disappointment. If there are electrolytic capacitors on your board, there's a good chance they were already destroyed by the water. They are not typically sealed to ward off immersion in liquids.

Re:There is hope

[supernova_hq]

Actually, I've found one of the best things to use is desiccant. It will provide an absolute zero moisture environment. Simply put some in the bottom of a bucket, then a layer of paper towel, then the electronics.

If you want to re-use the desiccant you can put it in the oven. When it comes out, it will be one piece (no longer powder), but you can break it up pretty easily (like chalk).

Re:There is hope

[Anonymous Coward]

work for a major manufacturer. We use a water based batch cleaning system to remove water soluble flux, however the same could apply to the original poster's case. Cleaning With Water: 1. Disassemble all of the components until you have bare PCB's. 2. Put them in a dish washer, without any soup.

Don't listen to him. I work for a major soup manufacturer. I recommend putting lots of soup in your dishwasher. Also, fill your car's gas tank with soup. (This is called "souping up" your car. All the real car lovers do it.) And why not buy an extra 100 cans of soup per week with your grocery shopping? Too much soup is never enough. BUY MORE SOUP.

Corrosion is inevitable.

[actionbastard]

Even though there was no power applied to these devices, the dissolved minerals in the water are enough to facilitate electrolysis between dis-similar metals and destroy the devices. You will be better off replacing the lot.

Ethanol

[Anonymous Coward]

Copious quantities of ethanol will help, possibly in more ways than one. :)

Distilled water is your freind

[crowtc]

I've had a lot of luck cleaning mold and other contaminants from electronics by disassembling the item as completely as possible, cleaning each peace with a gentle liquid cleanser of some kind (i.e. Windex) and a soft brush, then rinsing it thoroughly with distilled water.

I was recently able to recover a number of computers that had been in a fire and had been sprayed with water from a fire hose. They were a mess, but so far they all work (10 months and counting)

A lot of pessimists around here!

[GrahamCox]

Quite a few posters have said this is a write-off without even seeing the state of the kit in question. That's pretty pessimistic! Here's a tale that should give hope:

Many years ago I worked in the service department of an electronics OEM repairing stuff returned from the field. The OEM built two-way radios. One time we were sent a portable radio that had been recovered from the sea-bed having been dropped from an oil-rig in the North Sea six months previously. The unit had a die-cast zinc/aluminium chassis and case and standard double-sided PCBs with mostly discrete components and a few ICs. It was extremely corroded, covered in salty deposits, and naturally didn't work. I was written off immediately but as a 17yo with time on his hands I took it as a challenge. I cleaned up the unit by passing it through the tanks of hot trichloroethylene that were used for cleaning newly assembled boards. This removed most of the surface corrosion on the PCBs and chassis. An open-framed rotary switch for channel selection was replaced as it was too far gone.I ran the boards through the normal service/setup procedure. The receiver came up no problem with basic retuning. The transmitter was dead but only needed a new final stage transistor and a retune. It passed spec. It was returned to the customer along with a new replacement unit. They were astonished and very pleased with the customer service received beyond the call of duty or expectation. Whether it was connected I don't know but they placed a huge order with us several months afterwards...

The kit here was immersed in fresh water for much less time. While component densities are much higher in modern kit, I think there's a good chance it will work after careful cleaning and drying. Worth a shot anyway - what have you got to lose?

Re:dunking electroncis whole is a bad idea

[Martin Blank]

But the whole "down to the studs" thing is

Apparently, you found more water after turning the power back on.