GR 3750 Check Paper feed area

[cokwax]

Faulty Power supply caused a fault on my system PCB. Replaced both. Now getting an error at startup "controllare area presa carta" which I guess means check paper feed are. No paper is jammed, Papers loaded to tray but machine cannot work. Tried test mode 97 in vain. Is this caused by the change of system PCB? Any advice?

[filmplane]

Faulty Power supply caused a fault on my system PCB. Replaced both. Now getting an error at startup "controllare area presa carta" which I guess means check paper feed are. No paper is jammed, Papers loaded to tray but machine cannot work. Tried test mode 97 in vain. Is this caused by the change of system PCB? Any advice?

See this post here: it may be the safety bar switch:
Risograph GR 2750 Check Paper Feed Area advisory message won't go off

[cokwax]

See this post here: it may be the safety bar switch:
Risograph GR 2750 Check Paper Feed Area advisory message won't go off

Mine seems different issue. Safety bar switch is operating properly,Its switches click when pushed up and click again when released. Even its removal does not help.