Row 2 out. It is a board issue. Replaced q46 and still no go. Should I replace a different transistor? If so which one?
Row out
- Thread starter atariaction
- Start date
DRANO
Super Member
Describe the problem.
Is the entire row just not registering at all or are you getting false readings?
Have you confirmed the connector and header pin for that row are making good contact? Looks like it's 1J10-8
Is the entire row just not registering at all or are you getting false readings?
Have you confirmed the connector and header pin for that row are making good contact? Looks like it's 1J10-8
Where you're in London, just call Cooke to come and fix it. No sense chasing your tail and potentially doing more damage to the PCB.
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Corey and I have been working on this issue together. I'll describe in more detail...
None of the switches in row 2 are registering. The wiring and diodes all tested fine so we looked to the board.
There is continuity from the molex connector to the header pin 1J10-8 and from the header pin to the next component on the board (which I think was a transistor leg)
We did the jumper test using alligator clips and a diode. We jumpered column pins to row pins and all worked fine except for row 2 which did not register when jumpered.
Corey suggested Q46 was the issue. It tested fine but I changed it anyways and the issue is still there.
None of the switches in row 2 are registering. The wiring and diodes all tested fine so we looked to the board.
There is continuity from the molex connector to the header pin 1J10-8 and from the header pin to the next component on the board (which I think was a transistor leg)
We did the jumper test using alligator clips and a diode. We jumpered column pins to row pins and all worked fine except for row 2 which did not register when jumpered.
Corey suggested Q46 was the issue. It tested fine but I changed it anyways and the issue is still there.
I think changing any of those transistors is only going to help if you have a whole COLUMN out, not a row. You need to start looking at the resistor networks, specifically SR11. If that checks out you've likely got an issue with the 4011 IC's and using a logic probe and a schematic you should be able to find which one is causing you the problem. If those don't solve the problem then you're all the way back to the PIA that controls the matrix.
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