The A500 is completely fucked up. It would be a waste of time to try to do anything with it.
The A600 had a defective disk-drive that was fucking up the disks. After changing the drive, the problem remained, and there was no one who know how to fix it here. After sometime, turning it on would show only a white screen and nothing more.
Thosebig white power boxes (I dunno how they are called in english), I believe they aren't working too (Neither the A500 or the A600 one)