dansretropod
Member
Try removing the 2 large 6520 chips, they look like they're soldered in your earlier pictures though. 6520's are not needed to boot to the BASIC prompt. Several times I have had a PET that wouldn't boot because one of these was faulty.
I'd suspect the ROM's next, if there was something wrong with the screen or the CRT chip you would probably still get the chirp sound when you turn it on. Do you have access to an EPROM burner? Or another PET with BASIC 4 ROM's?
Again looking at your earlier pictures most of the ROM's look to be soldered onto the main board so you may have to do some soldering to fix this one. On my none-working 4032 I ended up removing all the soldered ROM's, CRT chip and both 6520's and put sockets in.
I'd suspect the ROM's next, if there was something wrong with the screen or the CRT chip you would probably still get the chirp sound when you turn it on. Do you have access to an EPROM burner? Or another PET with BASIC 4 ROM's?
Again looking at your earlier pictures most of the ROM's look to be soldered onto the main board so you may have to do some soldering to fix this one. On my none-working 4032 I ended up removing all the soldered ROM's, CRT chip and both 6520's and put sockets in.