In this video update iz8dwf is repairing a Commodore VIC-1540/1541 long PCB.
“Faults found are: one zener diode broken (maybe overheated?), one interrupted small signal diode, one missing connection from a previous chip substitution and one 74LS07 probably fake (or coming from a discarded/defective batch?). As always, I tried to explain as much as possible about the repair process and my reasoning during the troubleshooting.”