Hi, I'm new here. I was looking for a Macintosh classic II, and I found one for a good price. But, it has a problem. The announcer says it turns on but has a problem on the diodes due to the humidity and it's possible to work again. The question is:What is an diode? Can humidity affect diodes? What is the job of an diode on the computer? Is it easy to fix the problem? I hope somebody reply to my message. Thanks!