Blank Display - HP LaserJet II Serie Manual De Instrucciones

HP 33440/HP 33449 COMBINED SERVICE MANUAL
Blank Display
Ml information displayed on the printer's Control Panel is generated by the Interface/Formatter
(1/F) PCA. The I/F PCA provides dl voltages and display information to the Control Panel, and
the Control Panel cable connects the Interface/Formatier PCA to the Control Panel.
A blank display panel is the result of one of the following malfunctions:
E Service Mode was initiated with no follow through.
The printer cannot generate sufficient voltiges to illuminate (enable) the display panel.
The display panel, its related cabling, or its drive circuitry is defective.
Note
The test pattern produced by pressing the Test Print Button is exclusively created
by the DC Controller PCA. The printer's Control Panel and Interface/Formatter
~$
PCA may be removed from the printer and the test would still be functional. If a
print engine Test Print pattern can be created once the fuser reaches its operating
temperature and dl voltages are correct, the problem is more likely a defective
Control Panel, Control Panel cable, or Interface/Formatter PCA.
Table 7-3. Blank Display
1. Is the printer's ON/OFF switch set to ON?
2.
Is AC power available at the input power
receptacle?
Power ON printer.
Verify input power.
3. Is the power cord fully inserted in the rear of Veri@.
the printer?
4.
Is the Lower Cooling Fan operational?
(Indicates +5 and + 24A voltages are present.)
If no aitiow can be detected at the lower right
rear of the printer (below the Power Switch),
proceed with the DC Voltage Functional Check
which follows this table.
5. Are the + 5V and GND screws on the
Interface/Formatier PCA loose or missing?
6. Are the display electronics malfunctioning?
Verify that screws are fully tightened and that
voltage is available to the I/F PCA.
Perform the following steps while power-cycling
the printen
1. Remove any 1/0 mbles to the host system.
2. Reseat the Control Panel Cable.
3. Replace the Control Panel.
4. Replace the Interface/Formatter PCA.
5. Replace the DC Controller PCA.
6. Replace the Control Panel Cable.
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