HP LaserJet M1120 Service Manual - Page 148

Half self-test functional check, Perform a half self-test check, Perform other checks

Page 148 highlights

Half self-test functional check The print process can be subdivided into the following stages: ● Image formation stage (charges the drum and writes a latent image to the drum with the laser) ● Development stage (forms a toner image on the drum) ● Transfer stage (transfers the image to the media) ● Cleaning stage (removes excess toner from the drum) ● Fusing stage (applies heat and pressure to the media to make the image permanent) Perform a half self-test check The purpose of the half self-test check is to determine which process is malfunctioning. 1. Print a configuration page. 2. Open the print cartridge access door after the paper advances halfway through the product (approximately five seconds after the motor begins rotating). The leading edge of the paper should have advanced past the print cartridge. 3. Remove the print cartridge. 4. Open the print cartridge drum shield to view the drum surface. If a dark and distinct toner image is present on the drum surface, assume that the first two functions of the electrophotographic process are functioning (image formation and development). Problem solve the failure as a transfer or fusing problem. Perform other checks If no image appears on the photosensitive drum, perform these checks: 1. Make sure that you removed the entire length of the sealing tape from the print cartridge before you installed the cartridge. 2. Perform a drum-rotation functional check to ensure that the drum is rotating (see Drum rotation test on page 131). 3. Perform a high-voltage power-supply check. See Heating element check on page 133. 132 Chapter 6 Problem solve ENWW

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Half self-test functional check
The print process can be subdivided into the following stages:
Image formation stage (charges the drum and writes a latent image to the drum with the laser)
Development stage (forms a toner image on the drum)
Transfer stage (transfers the image to the media)
Cleaning stage (removes excess toner from the drum)
Fusing stage (applies heat and pressure to the media to make the image permanent)
Perform a half self-test check
The purpose of the half self-test check is to determine which process is malfunctioning.
1.
Print a configuration page.
2.
Open the print cartridge access door after the paper advances halfway through the product
(approximately five seconds after the motor begins rotating). The leading edge of the paper should
have advanced past the print cartridge.
3.
Remove the print cartridge.
4.
Open the print cartridge drum shield to view the drum surface. If a dark and distinct toner image is
present on the drum surface, assume that the first two functions of the electrophotographic process
are functioning (image formation and development). Problem solve the failure as a transfer or fusing
problem.
Perform other checks
If no image appears on the photosensitive drum, perform these checks:
1.
Make sure that you removed the entire length of the sealing tape from the print cartridge before
you installed the cartridge.
2.
Perform a drum-rotation functional check to ensure that the drum is rotating (see
Drum rotation
test
on page
131
).
3.
Perform a high-voltage power-supply check. See
Heating element check
on page
133
.
132
Chapter 6
Problem solve
ENWW