LaserJet 4V Error 51 after first page

[Michael Wilch]

I've got an old LaserJet 4V printer, which gives me an error 51 after
printing the first page.
When splitting a print job into single pages it will print it just fine, but
that's no solution.
The service manual says it is a "laser beam detection error" and suggests to
check the cables at the scanner unit. I've already done that (tweaked the
connectors of the sensor wire) and also cleaned the optics in the scanner.
The connection from the photo transistor to the DC-unit is now at 2 Ohms,
which I consider good.
I haven't measured the other cables at the scanner unit but tweaked the
connectors, too.

Is there anyone having experience with this fault? Is the problem maybe at
another place, power supply, bad capacitor at DC-unit or something else?

Thanks,

Michael


Xpost c.p.p, s.e.r
Fup2 s.e.r

 

[Tony]

I've got an old LaserJet 4V printer, which gives me an error 51 after
printing the first page.
When splitting a print job into single pages it will print it just fine, but
that's no solution.
The service manual says it is a "laser beam detection error" and suggests to
check the cables at the scanner unit. I've already done that (tweaked the
connectors of the sensor wire) and also cleaned the optics in the scanner.
The connection from the photo transistor to the DC-unit is now at 2 Ohms,
which I consider good.
I haven't measured the other cables at the scanner unit but tweaked the
connectors, too.

Is there anyone having experience with this fault? Is the problem maybe at
another place, power supply, bad capacitor at DC-unit or something else?

Thanks,

Michael


Xpost c.p.p, s.e.r
Fup2 s.e.r

I freseating the cbales does not help, the problem may be the laser scanner
itself not coming up to speed or even varying in speed. Also the DC controller
can cause this error.
Does the laser scanner come on briefly when you power the printer on? It makes
a distinctive noise. It should also come on when printing. The sound made can
sometimes indicate an issue, does it sound the way it used to or has the
scanner noise changed?
Tony
MS MVP Printing/Imaging