And if I can fall in electronic lingo, the CPU /RST signal is driven by this IC, through the two open-collector inverter gates of the 7405 you see in the second photo. And another hint to me is the faded away marking : overheating can conduces to such discoloration. And at last, I like to understand what I see : even if the source isn't here, an unmarked IC titillates my brain
It will be great ! Thanks you !I will try to get the schematics to you ASAP.