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 Initiate a self test.
2 Open the Printer Door after the paper advances half-way through the printer (about 8 seconds after the 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.) Troubleshoot the failure as a transfer or fusing problem.
If NO image is present on the photosensitive drum, perform the following functional checks:
1 Make sure you have removed the entire length of the sealing tape from the toner cartridge before you installed the cartridge.
2 Drum Rotation Functional Check.
3 High Voltage Power Supply Check.

7-22 Troubleshooting