A500 hardware issue

[HyAmi]

I have an A500 with a Viper520 and HD. Today, I tried to add a cdrom drive to the accelerator. When I tried to boot, the screen did not appear. When I removed the cable I did get 1 or 2 times the boot menu, but after that I haven't seen any sign of life on my monitor(1084). I use the composite port (both black & white and via the A520) but both do not work. I tried the monitor using a vcr, which learned me it was not the monitor. The computer seems to boot, as I hear the harddrive or floppy do all the usual things. Any idea what might have happened? Did the Denise quit working?

[HyAmi]

the caps lock light briefly turns on, and then off. What was on your mind?

[HyAmi]

I just found out that (after several hours not working) the system boots just fine, but after 1~3 minutes the screen will go white. On the accelerator, the 020 gets quite warm (it seems to be a factory overclocked processor (from 16MHz to 33MHz)), but when I cool it, the condition remains... Any ideas :-?