EPSON DX-5050 (etc):How to test part EPS-112E

[richard7677]

Switched on my old EPSON DX-5050 and no power light. Reading things on internet, I see that it quite likely is a power supply problem.

I have a circuit diagram and it looks like power ON/OFF is effected by a signal on PSC (Power Supply Control) on CN2.

Does anyone know what kind of signal needs to be on the line PSC? That line goes to CPU. Thanks.

EDIT: I suppose PSC would take a logical signal of some value.

 

[richard7677]

OK, the PSU actually works, because when it is connected to the printer and I press the ON button, the PSU outputs 42V. Voltage vanished when I stop pressing the ON button. I've had the ON button pressed for more than 50 seconds and still no ON light. So, the problem must be outside of the PSU. And if that is the case, I really do not have much choice but to throw away my DX-5050. I checked wire continuity between PSU and the printer. All fuses OK.