Blank Display

There are a couple of different types of symptoms that have been noted:
The display is completely black with no LED lights on.
The display menu prompts do not work, but the blue/black backlight is on and the LED lights are on solid.

A couple of causes have been identified, but this issue is still under investigation.

First, ensure memory dimms are properly seated. This has corrected some instances of blank display before.
Next, is this a replaced formatter? If after reseating the dimms, there is still a blank display, check that the jumper on the boot select pins (J53; top center of the formatter board) in the formatter is on the correct pins (TWO RIGHT SIDE PINS). Some cases have been noted where a replaced formatter has had the jumper on the two left side pins rather than to the right. This will cause a blacked out display and must be corrected.

Figure 1: Example of correct jumper position

Next, if the above suggestions do not bring back the control panel display, run an engine test page to verify that the printer engine is functioning.

Printing test pages helps you determine whether or not the printer engine and the formatter are functioning.

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 using the following instructions.

Use a small, non-metallic, pointed object to depress the test-page switch, which is located on the right side of the printer (callout 1).

The test page should have a series of vertical lines and should print from the last tray that you printed from. However, if the printer has been turned off and then on again 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 or Sleep mode.

NOTE: If the test page is successful, the problem likely resides in the formatter and will need to be replaced. If the formatter is removed and the engine test does not print a test page, the problem is likely NOT the formatter but the engine. Possible culprits are power supply or dc controller in this case. 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 formatter, the control panel, or the cable that connects them.

© 2005 Hewlett-Packard