HP Laserjet 4100 MFP No Display

[LT2000]

I have an HP 4100 MFP and the error message used to display 49.FF 81 and the display is no longer powered. The display worked briefly, then powered off, when I took the entire printer appart to get to the main board to check the fuses, (they were fine) and reassembled the printer, the display worked agian, only briefly, then powered down. The printer and scanner do a POST, and is capable of printing and performing an engine test without display.

We have replaced or tried the following.

- Replaced LCD display/control panel. - no result
- Replaced Formatter board. - no result
- Replaced firmware DIMM. - no result
- Replaced formatter cable. - no result
- Replaced HDD. - no result

All suggested courses of action by the HP service manual as possible problems for the error message and display problem.

Any help would be appreciated

[JJprinter]

Had a similar problem once no display
Took high pressure air and blew on the display panel to much dust behind panel and could not make contact with sensor worked fine after that.
you never know.

[AJacquez]

LT2000:

Did you ever find a solution? If so, what did you do to resolve the issue? I too, am experiencing the same problem and have replaced the same parts with no success.

Please help

[redcow]

You already pulled out the Engine Controller Board. Why didn't you change it?
If you read the service manual you would see that the operator panel plugs into the Engine Control Board (page 269)