asked Jun 5, 2009 at 1:33pm
Hp HP LaserJet IIIP+

HP Laserjet iiip printer

What does error code 51 indicate?

I've been told its the scanner motor. Is this correct?

If so how difficult is it to replace for a non-techy person.

51 is a beam detect error. That means the DC controller does not detect the presence of the laser beam. Here's where it gets a bit complicated. Normally, you would replace the laser PCA unit to fix the problem. In reality, the scanner motor causes the problem about 1/2 the time, so it's a 50/50 shot which one it is. Having worked on thousands of them, I can listen to the scanner motor winding up and determine if it is the cause of the 51 error. If you listen to it, it should be a smooth windup and then stabilize at a soft whine. Don't know why the scanner motor sometime causes a 51 error instead of a 52 rotational speed error, like it's suppose to give.
by moe on Jun 5, 2009 at 2:55pm Add comment
quite a few parts to dismantle with the iiip unfortunately. the laser scanner unit is sitting right in the heart of the printer.

since the printer is no good as it is anyway, try and see if you can do it before buying the new part. that is, take it apart till you get to the scanner, put it back and see if it's still going :)
by tk55 on Jun 5, 2009 at 3:07pm Add comment