Our ricoh aficio appears an error code of sc500 the technician told us to change the lower db unit I thoght t was the main motor why do we need to change the lower db unit not tne main motor im. so confused our unit is ricoh 2018.thanks

En allumant mon photocopieuse, après 5seconde la lettre sc500 s'affiche et ne fonctionne pas

Hi, SC500: Main motor lock
A main motor lock signal is not detected for more than 500 ms after the main
motor starts to rotate, or the lock signal is not detected for more than 500 ms
during rotation after the last signal

- Possible causes -

• · Too much load on the drive mechanism

• · Main motor defective

Sc 500 means main motor lock. this is normal for high copy volume printers. check the idler gear and developer gear of the pcu it is seldom the problem. here's the part no.
B039 3062 Idler Gear - 16z
B039 3060 Development Roller Gear
if this helps pls rate