Humidity ?

I've owned a Carver PM-900 SS amp for 12 years without ever having a problem. Recently(July2000)I flipped the power switch to turn it on and nothing would happen, dead. Two days later I flipped the switch and this time it went on. I didn't give that incident much thought because it worked fine after that, until now. It happened again, after three days, I took it out of my system and brought it down to my basement. I opened it up, but unfortunately I do not have the experience in diagnosing electronics. The only clue I have is that there was a period of high humidity in the area I live, before I tried to turn on the amp(second time). And a day later after I brought it down into the basement, where I run a de-humidifier, it was working again. Due to the amp's age(or any number of other factors), can humidity cause a problem like this to happen? If so, what should I look for? What possible remedies are available? Etc... Thanks in advance.