Hi,

I used to use a HP LJ4 for prototyping PCBs, but ive recently come
back to electronics after a long break and now the printer has a weird
fault.

Self-test works fine, but in PCB artworks an afterimage at 94mm can be
seen, as well as horizontal banding in the black areas, the banding
seems to be related to the amount of black on that line (more
black=lighter black).

Im told the afterimage is a sign the photosensitive roller is on its
way out, but Ive just put a spare toner assembley in it and its doing
the same thing with the replacement toner. While im not dismissing the
idea that the spare toner could have the same fault, im dubious its a
toner issue (and am a little unwilling to fork out £100 for a toner
cartridge to find out!)

Any ideas on what else it could be? My best guess on the banding would
be a worn out capacitor somewhere in the power supply to something,
and the after-image may be related to something like a roller not
getting power (eg the roller that neutralises the old image on the
drum before the new image is constructed), but im not ruling out a
toner cartridge problem - the spare came with the printer and was
unused (toner tab intact) but not in a black bag and handling has been
suspect (stored on its side for a while), so its possible the
cartridge is broken, but I dont buy it being broken in exactly the
same way as the other cartridge, and would probably look elsewhere.

Can anyone shed any light on this?

TIA for any help.

AlanH wrote:
I used to use a HP LJ4 for prototyping PCBs, but ive recently come
back to electronics after a long break and now the printer has a weird
fault.

You might ask in comp.periphs.printers or see
http://www.fixyourownprinter.com/ or http://www.printerworks.com/ .

Standard disclaimers apply; I don't get money from any of the companies
mentioned.

Matt Roberds

On Wed, 31 Aug 2005 07:10:33 GMT, wrote:
AlanH wrote:
I used to use a HP LJ4 for prototyping PCBs, but ive recently come
back to electronics after a long break and now the printer has a weird
fault.

You might ask in comp.periphs.printers or see
http://www.fixyourownprinter.com/ or http://www.printerworks.com/ .

And, there is: comp.sys.hp.hardware

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
Pueblo, Colorado | @ config.com | Jonesy | OS/2
*** I killfile X-Trace: posting.google.com followups in this ng

"AlanH" wrote in message
...
Hi,

I used to use a HP LJ4 for prototyping PCBs, but ive recently come
back to electronics after a long break and now the printer has a weird
fault.

Self-test works fine, but in PCB artworks an afterimage at 94mm can be
seen, as well as horizontal banding in the black areas, the banding
seems to be related to the amount of black on that line (more
black=lighter black).

Im told the afterimage is a sign the photosensitive roller is on its
way out, but Ive just put a spare toner assembley in it and its doing
the same thing with the replacement toner. While im not dismissing the
idea that the spare toner could have the same fault, im dubious its a
toner issue (and am a little unwilling to fork out £100 for a toner
cartridge to find out!)

Any ideas on what else it could be? My best guess on the banding would
be a worn out capacitor somewhere in the power supply to something,
and the after-image may be related to something like a roller not
getting power (eg the roller that neutralises the old image on the
drum before the new image is constructed), but im not ruling out a
toner cartridge problem - the spare came with the printer and was
unused (toner tab intact) but not in a black bag and handling has been
suspect (stored on its side for a while), so its possible the
cartridge is broken, but I dont buy it being broken in exactly the
same way as the other cartridge, and would probably look elsewhere.

Can anyone shed any light on this?

TIA for any help.


If 94mm is the circumference of the fuser roller then suspect the fuser temp
or contaminated fuser or broken fuser roller PTFE surface.
Copier & laser printer tips
http://www.divdev.fsnet.co.uk/copiers.htm


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Wed, 31 Aug 2005 02:24:09 GMT, AlanH
wrote:

Hi,

I used to use a HP LJ4 for prototyping PCBs, but ive recently come
back to electronics after a long break and now the printer has a weird
fault.

Self-test works fine, but in PCB artworks an afterimage at 94mm can be
seen, as well as horizontal banding in the black areas, the banding
seems to be related to the amount of black on that line (more
black=lighter black).

Im told the afterimage is a sign the photosensitive roller is on its
way out, but Ive just put a spare toner assembley in it and its doing
the same thing with the replacement toner. While im not dismissing the
idea that the spare toner could have the same fault, im dubious its a
toner issue (and am a little unwilling to fork out £100 for a toner
cartridge to find out!)

Any ideas on what else it could be? My best guess on the banding would
be a worn out capacitor somewhere in the power supply to something,
and the after-image may be related to something like a roller not
getting power (eg the roller that neutralises the old image on the
drum before the new image is constructed), but im not ruling out a
toner cartridge problem - the spare came with the printer and was
unused (toner tab intact) but not in a black bag and handling has been
suspect (stored on its side for a while), so its possible the
cartridge is broken, but I dont buy it being broken in exactly the
same way as the other cartridge, and would probably look elsewhere.

Can anyone shed any light on this?

TIA for any help.

I have posted the Laserjet 4,5 (M,N,Plus) combined service manual on
one of my websites just for you.

It's in PDF format.

With any luck, this 453 page manual will help...
Failing that, clean the corona wire.

See:
http://web.newsguy.com/MichaelGray/