No display and no light indicators when powered on
If the printer control panel is blank when you turn on the printer, check the following items.
1. Make sure that the printer is plugged into an active electrical outlet that delivers the correct
2. Make sure that the on/off switch is in the on position.
3. Make sure that the fan runs briefly, which indicates that the power supply is operational.
4. Make sure that the control panel display wire-harness is connected.
The control-panel wire-harness connector can easily be disconnected when you install the top
cover. If the control panel does not work after the top cover is installed, verify that the wire-harness
connector is fully seated into its DC controller PCA connector.
5. Make sure that the firmware DIMM and the formatter are seated and operating properly.
6. Remove any HP Jetdirect or other EIO cards, and then try to turn the printer on again.
If the printer control-panel display is blank, but the main cooling fan runs briefly after the printer
power is turned on, try printing an engine test page to determine whether the problem is with the
control-panel display, formatter, or other printer components.
Engine test page
To verify that the printer engine (all printer components except the formatter, formatter DIMMs,
EIO products, and the stacker or stapler/stacker) is functioning, print an engine test page. Use a
small, non-metallic, pointed object to depress the test-page switch, which is located on the right
side of the printer
The test page should have a series of vertical lines. The test page will print from the last tray you
printed from. However, if the printer has been turned off and then back on since the most recent
print job, the page will print from tray 2. The printer will continuously print test pages as long as
the test-page switch is depressed. The printer will not print a test page if it is in PowerSave
A damaged formatter might interfere with the engine test. If the engine test page does not print,
try removing the formatter and performing the engine test again. If the engine test is then
successful, the problem is almost certainly with the control panel, or the cable that
Hope this helps
May 24, 2008 |
HP LaserJet 4250n Printer