Dear CNC Guys,

Our FANUC OM (model B) stopped working: the screen is blank and there is no diagnostic whatsoever.
(When switching off - the CRT flashes a little, so we can see that it was a kind working but did not have a signal)

On master PCB there are 3 LEDs: SI SO and WD (red greed red) and all of them are off.
The power supply is Ok - we checked the voltages.

Any hint how to trace the problem will be greatly appreciated.

With kindest regards, Igor