Gest./Tosh. Cs or Sc-331 color c38

[SKTeK315]

Hi everybody. Gest. Color 331, also a Tosh. C38 code. Anyone ? Thanks

[FASTSTI]

c31- Used toner transport motor rotation abnormal
C38 Auto-toner error BLACK

[SKTeK315]

Gest cs331 sc38

Where is the bk auto toner sensor & what can I do thru srvc mode & which 1.
Thank. I've got another cs-331. That's calling for Bk maint. Can I prolong it & how do I clear it with out doing pm ?
Thanks