Herman Pattersen

asked Feb 6, 2016 at 10:51pm
Hp HP LaserJet 4

Error 51 Beam Detect Failure

Cannot seem to get this fixed. First carefully checked the cables to the scanner. Then replaced the scanner assembly. Then replaced the controller board. Rechecked the cables. Shutter works properly. Using a camera that sees IR, can see no evidence of a beam. Must be something else. What could it be? I have a scope if anyone knows what to look for. Thanks.

I have never seen a scanner assy. go bad on one of those printers. I would suspect the DC controller board as that provides the voltage to the scanner assy. and displays the error codes as well. I've replaced quite a few of those.

by moe on Feb 7, 2016 at 7:37pm Add comment