snuci
Veteran Member
I acquired a SuperPET sometime ago and I've been trying to fix it but this one is a little weird. I've removed the BMB board and the Computhink boards and am focused on the 8032 board at the moment.
I know the monitor works fine as well as the power supply because if I put in another 8032 motherboard, it works fine.
I have a ROMulator to help me troubleshoot (it's really awesome)
- If I set up the ROMulator to emulate the ROMs and memory for an 8032, I get a start up beep but no video.
- If I set up the ROMulator to emulate the ROMs and memory but with the PETTESTER ROM, I get nothing on screen
- I've checked to make sure that the CRTC chip works in another machine and it's fine.
- I've replaced some of the memory that was bad in that I checked the first 8 chips and 6 were bad but I suppose I should check all of it. I figured the PETTESTER ROM would help me identify the other bad chips so I wouldn't have to desolder all of it to check it.
- I've checked J7 and have 20khz on pin 5 and 60Hz on pin 3. I get nothing on pin 1 but it's not in the schematics that I can see easily.
I guess my first question is, does the start up beep indicate that the PET is running properly? Without any video, I cannot tell.
Any help is much appreciated.
Santo
I know the monitor works fine as well as the power supply because if I put in another 8032 motherboard, it works fine.
I have a ROMulator to help me troubleshoot (it's really awesome)
- If I set up the ROMulator to emulate the ROMs and memory for an 8032, I get a start up beep but no video.
- If I set up the ROMulator to emulate the ROMs and memory but with the PETTESTER ROM, I get nothing on screen
- I've checked to make sure that the CRTC chip works in another machine and it's fine.
- I've replaced some of the memory that was bad in that I checked the first 8 chips and 6 were bad but I suppose I should check all of it. I figured the PETTESTER ROM would help me identify the other bad chips so I wouldn't have to desolder all of it to check it.
- I've checked J7 and have 20khz on pin 5 and 60Hz on pin 3. I get nothing on pin 1 but it's not in the schematics that I can see easily.
I guess my first question is, does the start up beep indicate that the PET is running properly? Without any video, I cannot tell.
Any help is much appreciated.
Santo