papapopop
Member
Hi,
when repairing a PP board or PP_II, the watchdog often resets the Z80 continously. An easy way for disabling is cutting off CR4 on the CPU board. Now it is better to make any measurements. There is "no one" who recognizes if the watchdog runs (no watchdog for the watchdog!). Eliminating 6A 74LS161 also works fine. When the board runs, I would enable the watchdog again. Think this prevents some chips on the pcbs from damage when something is wrong.
Good luck for repair.
Greets to All
when repairing a PP board or PP_II, the watchdog often resets the Z80 continously. An easy way for disabling is cutting off CR4 on the CPU board. Now it is better to make any measurements. There is "no one" who recognizes if the watchdog runs (no watchdog for the watchdog!). Eliminating 6A 74LS161 also works fine. When the board runs, I would enable the watchdog again. Think this prevents some chips on the pcbs from damage when something is wrong.
Good luck for repair.
Greets to All