My AIWA CXNA71U, after being unplugged, did not turn on anymore. I took if for AIWA service in Brazil, and they coudn`t fix it. I ste it aside for one year, and then after plugging in, it worked again. But I have to take it for another place, and then, it happened again. It is plain dead.. no lights.. although I can hear the AC transformer vibrating. I got the schematics. May anybody help?

Do you have any electronics experience?

In my (so far limited) experience, a device that will turn on one moment, but not another (and usually will stay on once it is turned on) is likely bad capacitors. In some cases, you can visually see which ones are bad, defined by bulging on the top.