On Friday, May 13, 2022 at 4:52:29 AM UTC-7, phigan wrote:
> On 2022-05-08, Kenzo  wrote: 
> > Thanks, I ordered a zoomfloppy today.
> I'm really liking this thread. 
> 
> Just wanted to chime in that I too have a C64 that powers on with just a 
> black screen. I tried changing out the VIC and that made no difference. 
> Even tested the original as well as relacement VICs in a known good 
> system, and they both work fine. The first suggestion I got was to try 
> replacing the PLA, which I did, and also made no difference (also tested 
> that in the known good system). I don't _see_ any issues with any of the 
> caps on the board, but that doesn't necessarily mean there aren't any. 
> 
> I'd be very interested to hear what's causing yours to do the same if 
> you should find out :). 
> 
> Jelly of your C= collection! Never had a 128.
One book I have says a bad 6502 can also cause a black screen.  I guess the moral of your story is you really have to troubleshoot electrically, just replacing arbitrary chips is not guaranteed to solve the problem.  I have the documentation and 
equipment so I will be doing that soon and will update progress here.

--- SoupGate-Win32 v1.05