I’ve repaired a lot of Mars and Coinco validator with water damage to the upper and lower boards. Most of them are from Texas and they are nasty. 9 times out of 10 they are beyond repair, the screws are rusted in so when try to get them apart the frame will break. When you have customers who put the nozzle right into the bill validator bezel and let it rip you’re going to have water damage. I’ve been coating the boards so they aren’t as susceptible to damage, this has helped somewhat. Most of the time the water damage (corrosion) is on the leading edge of the lower and upper boards, sometimes they can be repaired, but not always. The main board gets the corrosion on lower portion of the board. It almost looks like the water wicks up the board. If you have bill validators in the bays you want to have at least one spare validator. The nice thing about Mars is the validator frames are all the same, if you want to change the model of the validator all you have to do is change the bezel, as long as the voltage is the same. I have a customer who is using Mars AE2602 24 volt in his Goldline ACW he has a spare for the Goldline and he needed a validator for his bay box. He wanted me to next day air him a validator, I told him to use his spare validator for the Goldline, all he had to was change the bezels.