CLP-775ND

[Arcadian]

I have a CLP775ND

Ive taken it apart and changed almost every part that has to do with power.

Ive changed Main PBA, Cartridged, ITB, Sub Power, HV PSU, LSU.
Still no black is printed, the color works fine, Cyan, Yello, Magenta.

I dont understand why the black wont print. Sporadically ill i slight image on the paper but nothing solid, most time a blank page.

See if anyone seen this or knows a solution.

Thanks

ARCADIAN