I was given a defective PS One (PAL, SCPH-102, PM-41 board) which didn't read discs at all. It somehow work with original games after lubricating and "pot tweak" the laser unit. But it's weird, some games only boot sometimes or after another game if I let the console rest for some hours. Like Crash Bash always boots, but Bugs Bunny Lost in Time only sometimes and after Crash Bash is played. And Bust-a-Move 2 most of the time is detected as audio CD instead of a original game.
Then I tried to get backups working. Because I only have a spare 12F629 PIC I programmed a MultiMode3 modchip. So far I understand the MM3 used on a PAL PS One (SCPH-102) should work, but only for playing PAL backups because of the region lock in the BIOS? But I can't even get PAL backups to work. Some are detected as audio CD's (like Tekken 3, WipeOut 3, Spyro) and some give the red screen with "Insert PlayStation format disc" (like Crash Bash). I checked the modchip connections matching this one (https://quade.co/ps1-modchip-guide/mm3/pm-41/) and no short circuits.
Is the modchip not working or is it only a worn CD drive problem?
Then I tried to get backups working. Because I only have a spare 12F629 PIC I programmed a MultiMode3 modchip. So far I understand the MM3 used on a PAL PS One (SCPH-102) should work, but only for playing PAL backups because of the region lock in the BIOS? But I can't even get PAL backups to work. Some are detected as audio CD's (like Tekken 3, WipeOut 3, Spyro) and some give the red screen with "Insert PlayStation format disc" (like Crash Bash). I checked the modchip connections matching this one (https://quade.co/ps1-modchip-guide/mm3/pm-41/) and no short circuits.
Is the modchip not working or is it only a worn CD drive problem?