Toshiba e-STUDIO 4500c, Service Manual

Page: 394 / 1120

SPECIAL PROCEDURES April, 2007
4-16
4.2.4 PROCESS CONTROL TROUBLESHOOTING
Summary of Process Control SC Codes
This is a list of SC codes that may occur during process control. For more, please
refer to the process control tables on the following pages.
Pre-Processing Check
SC316 to SC319 Vpp is not within the normal range (Vpp: the AC current applied to the
charge roller to compensate for changes in the ambient temperature and
humidity). Insufficient charge causes white spotting and too much charge
causes toner to film on the surface of the drum. Vpp must be > 2.8 kV.
SC400 ID sensor could not be calibrated. An abnormal ID sensor condition is
detected when before calibration begins, Vsg < 0.5V or after calibration, Vsg
cannot be adjusted to 4.0
±
0.2V.
SC418 Correct current could not be supplied to the ID sensor.
SC436 to SC439 A problem is detected with a potential sensor during calibration.
Potential Control
SC410 to SC413 The development gamma is out of range (not between 0.3 and 6.0) for a
color.
SC414 to SC417
Vk is out of range (not within
±
150V) for a color. If the development potential
is less than Vk, toner is not applied to the drum.
SC420 to SC423 Vd cannot be adjusted to the target voltage for a drum.
SC424 to SC427
The potential sensor detects that Vpl is not
±
10V of the target Vpl after
exposure of the ID sensor patterns.
SC432 to SC435 The residual voltage on a drum is greater than -200V.
TD Sensor Output Calibration
SC360 to SC367 An abnormal condition is detected when output of one of the TD sensors
fails to fall within the range of 0.5V to 4.5V.
Process Control Gamma Correction
SC410 to SC413 The development gamma for black, magenta, cyan, or yellow is not within
range (0.3 to 6.0).
SC414 to SC417 The development start voltage (Vk) for black, magenta, cyan, or yellow PCU
is not within range (
±
150V)