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

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: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.