Kyocera CS2552 Error C7301 (Wierd)

[tecchie]

I'm having a weird issue with a CS2552 error C7301 i can use some input with.

Initial problem was grinding noise when copying/printing then error out
Checked for any clogging (waste toner auger unit, transfer cleaning assembly and toner supply unit)
Found clogged toner supply assembly on black side. Vacuumed out and tried. Still noise (not as bad) and eventual C7301
Replaced toner supply assembly. Ran U135 all 3 functions working properly. Getting washed out b/w copies/prints and c7301 after copying.
Ran forced toner supply which starts but then throws the C7301. Not sure if this is because black dv is starving of toner.
Tightened all electrical connections
Haven't tried new black dv unit. Not sure if they go bad if starved of toner for awhile
Thought it may be a board issue but U135 tests all functions which tells me all is fine.
I left my customers office with the copier running with no code after copying or printing but basically a blank b/w copy/print
Can i manually add black toner to try to rejuvenate dv unit (if that may be the problem) because the force toner cycle still does not work.

If anyone has run into any of this i would appreciate some input. Thanks.

[Ropariva]

Run U89 and check the print quality. I suspect your dev. I’ve had many of these fail prematurely. The seal fails at the gear end causing dev to leak and destroys the gears and can seize. . Toner has likely backed up as the dev unit isn’t allowing toner to drop into it for some reason.