submerged electronic..need help!

[krn]

hi. mass airflow sensor was submerged in the flood. can i still repair the circuit board inside? i dont have any idea about soldering or electronics. how can i make the circuit board inside running again? it was already three months after the flood. (auto mechanic told me there was a problem with the sensor). can i use any electronic cleaning device? can i still replace the parts?

[Hero999]

It depends on the device and whether there's a lot of corrosion on the metal parts or not.

Water isn't normally a problem unless it's very salty or the appliance is submerged whilst power is applied.

In the electronics  industry, circuit boards are frequently washed with water, it's normally deionised to help prevent corrosion. I don't have any deionised water and have washed circuit boards with tap water before drying with a hair dryer and I haven't had any problems.

Wash the PCB with tap water to get rid of any dirt and dry it as quickly as possible. Inspect the PCB, repair any corroded connections and hope for the best.

[awright]

As Hero999 says, cleaning with water is acceptable.  I first remove or protect any components that could be damaged by water, spray with a detergent solution, scrub with a toothbrush, rinse very well, then finally rinse with distilled water (available by the gallon at your local supermarket - it's used in clothes irons), then dry gently but thoroughly.

Pay special attention to cleaning inside any pots or other components with cavities that might have gotten filled with dirty water or mud, both in cleaning and in rinsing.  Use a low viscosity cleaner-degreaser detergent that will rinse easily, rather than a viscous dish soap that might resist rinsing. 

Potential problem areas are transformers that can be very difficult to rinse and dry adequately because the solution will penetrate the coils and transformer laminations (but I imagine that you don't have transformers in an automotive device).  Rather than trying to dry quickly with a hair dryer, I recommend slow but thorough drying over several days in a warm (not hot) place like in a sunny place indoors, near a lamp, or near a heater outlet that's not too hot.  The object should never get too hot to grasp comfortably for an extended period (as a temperature test).

Still, no guarantees if the object had been submerged for an extended period that led to corrosion.
Good luck.

awright