Controlling The Bias For The Transfer Guide And The Bias For The Fixing Roller - Oce 3121 Technical & Service Manual

5 Controlling the bias for the transfer guide and the bias for the
fixing roller
Bias for the transfer guide
The negative bias (-600 V DC) for the transfer guide is used to prevent adhe-
sion of toner to the transfer guide. The same potential is applied to the toner.
Application of the bias continues when the control panel power remains ON.
Bias to the lower fixing roller
A positive bias is applied to the steel core of the lower fixing roller. This is to
prevent offset to the fixing film.
The electrode terminal on the end of the lower fixing roller shaft is for this pur-
pose. Pay attention to the orientation of the lower roller if you have removed it.
Composite power supply PCB
DC controller PCB
506 TSM Océ 3121
T101
T101
drive
circuit
Q605
CPU
J209-A4~A9
J102-A4~A7
IC101
CPU
Fixing Photosensitive
drum
assembly
Transfer
guide
Functional description