"Stephen" wrote in message
o.uk...
Would this be with the ribbon cable disconnected between the main board
and the PSU board?


With the ribbom cable disconnected, measuring at Main board end:
What is these resistances:
pin 1 to pin 2 0.05 ohms. this is as expected as pins 1 and 2 are
soldered together at the main board
pin 1 to pin 4 380kohm
pin 1 to pin 7 1.4 Mohm
pin 1 to pin 8 1.2 Mohm

With the ribbom cable disconnected, measuring at PSU board end:
What is these resistances:
pin 1 to pin 2 0.05 ohms. this is as expected as pins 1 and 2 are
soldered together at the PSU board
pin 1 to pin 4 180Kohm
pin 1 to pin 7 1 kohm
pin 1 to pin 8 1 kohm

With the ribbom cable CONNECTED, measuring on the ribbon cable:

What is these resistances:
pin 1 to pin 2 0.05 ohms. this is as expected as pins 1 and 2 are
soldered together at the main board
pin 1 to pin 4 340 kohm
pin 1 to pin 7 1 Kohm
pin 1 to pin 8 1 Kohm

All of the above readings are not steady, so I geuss there are capacitors
charging/discharging via the multimeter.