adding to Panthera's post...
I also repair boards from time to time. Particularly Fisher & Paykel top loaders.
I often see moisture damage, both on power boards (the main board that does the switching of pump / valve / motor); and display boards with the control button microswitches.
FP machines have a membrane panel covering indicator lights and touch buttons, but they are not membrane switches, there are separate micro switches for each button. What happens over time is that the most frequently used buttons (power and start) get cracks in the membrane and moisture gets in to the microswitch, creating an erratic connection. I have a few dead boards on hand from which I pinch the less used microswitches like delicate, favourites and delay start. They are all the same little switch. Easily soldered in place.
On power boards I see the signs of dampness causing shorts between copper tracks, with corroded copper and sometimes weird discoloration of solder joins.
I am currently fixing a 10 year old Electrolux front loader, it needed new shocks which I fixed, but when final testing it was doing some seriously weird stuff.
[Most washer faults are simple observations like "won't spin", "won't fill", "noisy on spin" and so on. When the observations are that the machine is behaving completely bonkers, I generally suspect moisture damage to circuit boards as it so often turns out that a bit of moisture is taking voltage where it shouldn't be going, with confused microchips the result.] The Electrolux was stopping occasionally for no apparent reason, and sometimes at end of cycle it would just start the cycle again. (an all-electronic model with no timer dial). I opened up the main board and found a bit of moisture inside the plastic housing, and black sooty deposits on the circuit board looking like a component had exploded, but all components appeared intact. I guessed some water had got on the board, possibly even when I tipped the washer on its side to get it in my car. When I powered it up it flashed across the moist bits and created black sooty deposits that conducted enough voltage to confuse the microcomputer. I cleaned off the board with circuit cleaner spray, then dried it off overnight. Next day all OK, I have done 2 loads of washing in it with no further faults.