HP COLOR LASERJET 2820-2830-2840 Test mode and service mode - Printer Repair

HP COLOR LASERJET 2820-2830-2840

Engine test
The purpose of the engine test is to determine which image-formation process is malfunctioning. The image-formation process can be divided into the following stages:
# Conditioning stage (charges the drum)
# Writing stage (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 paper)
# Separation stage (separates the media from the drum)
# Fusing stage (applies heat and pressure to make the image on paper permanent)
# Cleaning stage (removes excess toner from the drum)
The engine test switch is inside tray 1, on the left side, just below the front cover.
To print an engine test:
1. Turn off the device.
2. Turn on the device.
3. Open tray 1 and load paper.
NOTE: If tray 1 is empty, the device will not perform an engine test. You cannot perform an engine test from optional tray 2.
4. Press the engine-test switch

NOTE: The formatter must be connected to the power supply cover plate to perform an engine test. Otherwise, the device does not print the engine test.
The device prints an engine-test page that contains four columns of horizontal lines, with each column corresponding to one of the print cartridge colors.
Half self-test check
If an engine test reveals a problem with the image-formation process, the half self-test check allows you to narrow down the area in which the problem exists.
To perform a half self-test check, complete the following steps:
1. Perform an engine test. See Engine test.
2. During the engine test, open the cartridge door after the paper advances halfway through the device (about five seconds after the motor begins rotation). The leading edge of the paper should have advanced past the imaging drum.
3. Remove the imaging drum.
4. Open the imaging drum shield to view the drum surface. If a dark and distinct toner image is present on the drum surface, assume that the first three functions of the image-formation process (see the list at the beginning of Engine test) are functioning (through the development stage). Troubleshoot the failure as a transfer or fusing problem. If, during the half self-test check, no image is present on the imaging 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 cartridge high-voltage contact test
Heating element test
Paper passes between the heating element and a soft pressure roller to fuse toner to the paper.
1. Unplug the device for at least ten minutes, and then remove the fuser
2. Measure the fuser heating element resistance.
NOTE: Normal resistance is 14 ohms +/- 10 ohms for the 110 V device and 50 ohms +/- 20 ohms for the 220 V device.

3. Measure the thermistor resistance.
NOTE: Normal resistance is 1.5 ohms.
If no resistance is measured, replace the fuser.
Cartridge high-voltage contact test
To check the print cartridge connection points, complete the following steps:
1. Turn the print cartridge over and visually inspect the two connection points on the ends of the print cartridge. If they are dirty or corroded, clean the connections. If they are damaged, replace the print cartridge.
2. If the connection points are dirty or corroded, then clean the connections. If they are damaged, then replace the print cartridge.
Service-mode functions
Use the following information to perform system-wide reset procedures and to adjust certain global settings such as the country/region. Users do not have access to this information.
NVRAM initialization
An NVRAM initialization will return the device settings to the factory-set defaults, including:
# All menu settings, including the fax header and company name
# Fax numbers and names that are associated with one-touch keys and speed-dial codes Additionally, all faxes stored in memory are cleared.
1. Turn off the device.
2. Simultaneously press and hold the ENTER button and the * button, and then turn on the device.
3. Wait until the message Permanent storage init. appears, and then release the ENTER and * buttons.

When the NVRAM initialization process has been completed, the device control panel shows the Ready message.
To print secondary service reports
1. Make sure that the control-panel display reads Ready.
2. Press MENU.
3. Press 2 on the keypad
NOTE: You can gain access to the secondary service menu from any other menu by pressing 2
4. Use the < or > button to select Service Reports, and then press Enter.
5. Use the < or > button to select one of the following reports:
# Cont. Self-Test
# Extended Keymap
# Error Report (see Error log)
6. Press Enter to print the report.
7. To exit the secondary service menu and remove it from the menu tree, press CANCEL to return to the Ready display, and then press CANCEL again.
To reset the device location
The device location setting affects telecom (fax) and other settings, depending on the country/region in which the device is used. To change the device location setting, complete the following steps.
1. Make sure that the control-panel display reads Ready.
2. Press MENU.
3. Press 2 on the keypad.
NOTE: You can gain access to the secondary service menu from any other menu by pressing 2.
4. Use the < or > button to select Location, and then press Enter.
5. Use the < or > button to select the country/region in which the device is operating, and then press Enter.
6. Press 1 to select Yes.
The device turns off and then turns on. When the device returns to the Ready state, it reflects the new location setting.
To test the control-panel display
To test the control-panel display and ensure that all characters are working correctly, complete the following steps.
1. Make sure that the control-panel display reads Ready.
2. Press MENU.
3. Press 2 on the keypad.
NOTE: You can gain access to the secondary service menu from any other menu by pressing 2.
4. Use the < or > button to select Display test, and then press Enter.
The device cycles through 15 characters at a time until the test is complete. To view the firmware version
Use the secondary service menu to determine the device firmware version.
1. Make sure that the control-panel display reads Ready.
2. Press MENU.
3. Press 2 on the keypad.
NOTE: You can gain access to the secondary service menu from any other menu by pressing 2.
4. Use the < or > button to select Show FW Version, and then press Enter.
The control panel shows the device firmware version number.
To enable or disable the memory-card slots
NOTE: This procedure applies to the HP Color LaserJet 2840 all-in-one only.
1. Make sure that the control-panel display reads Ready.
2. Press MENU.
3. Press 2 on the keypad.
NOTE: You can gain access to the secondary service menu from any other menu by pressing 2.
4. Use the < or > button to select Memory Cards, and then press Enter.
5. Use the < or > button to select Enabled or Disabled, and then press Enter.
To calibrate the color
1. Make sure that the control-panel display reads Ready.
2. Press MENU.
3. Press 2 on the keypad.
NOTE: You can gain access to the secondary service menu from any other menu by pressing 2.
4. Use the < or > button to select Color Cal., and then press Enter.
5. Use the < or > button to select one of the following settings:
# Contrasts
# Highlights
# Midtones
# Shadows
Press Enter.
6. Use the < or > button to select one of the following color settings:
# Cyan density
# Magenta density
# Yellow density
# Black density
Press Enter.
7. Use the < or > button to adjust the density setting. Increasing the setting darkens the density, while decreasing the setting lightens the density.
8. Press Enter to save the setting