EXP Computer C4077-90960 - Manual (Page 311)

Image System Troubleshooting
Half Self Test Functional Check
The electrophotographic process can be subdivided into the following stages:
•
Cleaning (removing excess toner from drum surface)
•
Conditioning (placing a uniform electrical charge on drum)
•
Writing (laser strikes surface of drum to create latent image)
•
Development (formation of the toner image on drum)
•
Transfer (charge to transfer the image to paper)
•
Fusing (heat and pressure to produce a permanent image)
The purpose of the Half Self Test Check is to determine which process is
malfunctioning. Perform the test as follows:
1 Print a PCL Configuration Page from the Control Panel Test Menu.
2 Open the top cover after the paper advances half-way through the printer
(about five seconds after the Main Motor begins rotation). The leading edge
of the paper should have advanced past the toner cartridge.
3 Remove the toner cartridge.
4 Open the toner cartridge’s drum shield to view the drum’s surface.
If a dark and distinct toner image is present on the drum’s surface, assume
that the first four functions of the electrophotographic process are
functioning (cleaning, conditioning, writing and developing - see Chapter 5),
and troubleshoot the failure as a transfer or fusing problem.
If NO image is present on the photosensitive drum, perform the functional
checks on the following pages:
7-74