I have 2 sys7 driver boards that prevent the mpu from booting.
When booting the blanking signal goes high and then back to low. Sometimes I can hear the relay click.
Using the pincoder blanking test I get a pass on the mpu itself and a fail with the driver board connected?
So could be 2 issues?
1. Something in the blanking circuit is pulling the signal low
2. Something on the board is crashing the running program and it stops feeding the clock and blanking stop.
I did see a suggestion that you could leave the board powered up and see if any of the ics heat up.
Or look for damage and remove the ics in that circuit.
Any tips or tricks to try here?