Minolta DI200f C0500 errors

[Will]

Keep getting C0500 errors every couple of days. Have replaced the fuser
heater lamp, fuser thermister, and thermal fuse. Can reset it and it works
for a day or two and faults out again with C0500. Can anyone suggest mostly likely probem????

[Si@danwood]

Door Interlock switch on the right hand side most likely there is a post somewhere on here that covers this...Si