Konica 7022 error codes

[Rigger]

error f-51-4

What fixes error F-51-4?

Please tell me what fixed the F-51-4 error. I have a customer with that error on a Konica 7033 and I hope it will go easy for them. They can't afford to replace it or pay for an expensive repair. I service many makes of copiers but few Konicas. The dealer went out of business and quit a few customers were left hanging.
Thanks

[Luther]

Take the back cover off and clean developer drive clutch ,bushings and shafts,also make sure developer unit isnt bound up, good luck

[Rigger]

Thanks, I'll try that. I appreciate the response!
Rigger