lidnariq wrote:
This isn't something I've previously tried to debug; my two NESes don't seem to show jailbars. (I also don't play enough to really notice)
But to the best of my memory, the big thing is: replace the electrolytic capacitors.
In subsequent major revisions of the mainboard (NES-101 and AV Famicom), they accidentally ran the video trace parallel with some of the PPU control signals, so there the only solution is completely cutting the video trace and rebuilding the amplifier, but that's not true on the only European PAL (or SCART) model.
So you mean getting back from PPU pin 21 and rebuilding the entire line (transistor ans so on) ?
This console is à French nes. It seems to be a more recent one Nes-CPU-11 but as far as I can say the pcb design is exactly the same as all the other French NES...
I have tested the video directly out Q1 in composite and even though the jailbars are much less visible, they are already there.
Before q1 the signal is so week that that it s hard to see if the jailbars are there.
Could there be something before the PPU that would ultimately caused the PPU to display a slightly corrupted image like this ?
Thanks again for your help.