hp LJ5 ERROR51

[Jeannette]

:confused: I have an HP LJ% erro 51. I am told I have to replace the Laser assembly, but I can't find instructions on how to do it? Any suggestions?

Thanks

[Brian]

Jeannette, first I would clean the optics in the laser unit, error 51 is a 'loss of beam detect' error, Laserjet 5's sometimes do get this problem, most of then I have fixed by cleaning the optics.

[Jeannette]

Thanks Brian,
I don't have instructions on removing it or even locating it.

[Brian]

http://www.printertechs.com/tech/assemblies/ex/1ex-output.php
Here you will find instructions on how to remove the output assembly, you'll need to follow this procedure first, after you have done this you will see a black 'box' with a big yellow sticker on it, this is the laser unit, it is attached with four screws, be careful with the cables that run over the unit.
The top of the unit has a spring on one side, remove this carefully, it also has one screw and is clicked in into four slots, you'll need to pry it open carefully with a flat screwdriver.
Once opened you'll see some lenses and mirrors, clean these with a cotton bud.
There are a few beam detect sensors on the sides it's imperitive that you clean these as these are likely to be the cause of the error.