robert_sissco
Experienced Member
I did a Vicky-Twenty build, and when I turn it on I got no picture. So, noting that this is a possibility, I installed the optional capacitor on the back of the board, now when I turn it on I get a blank, flickering screen.
I have a MOS produced VIC-20 CR board with the 6502, VIC, ROMs and PIA's all socketed, so when I switched them between boards, they all worked in the known working board, and I get the same issues on the Vicky-Twenty build board with the chips from the known working board, so it is something on the board itself. I can set up and shoot a bit of video later today, but since the issue seems to be on the board itself, any idea on where to start looking?
I do not yet have a scope to check signals, but I go have a logic probe. Since the issue appears to be with the video, I assume it is somewhere with that circuitry, but I am not sure where to begin.
I have a MOS produced VIC-20 CR board with the 6502, VIC, ROMs and PIA's all socketed, so when I switched them between boards, they all worked in the known working board, and I get the same issues on the Vicky-Twenty build board with the chips from the known working board, so it is something on the board itself. I can set up and shoot a bit of video later today, but since the issue seems to be on the board itself, any idea on where to start looking?
I do not yet have a scope to check signals, but I go have a logic probe. Since the issue appears to be with the video, I assume it is somewhere with that circuitry, but I am not sure where to begin.