NeXT (Almost-up-and-running-now) Laser Printer - test-drb@ccmp.vtda.org

18 Apr 2002

On April 18, Christopher Smith wrote:
...
  I'm certain that this problem comes from the
printer setting
 too long, and making an indentation in the rubber on the 
 roller.  Has anyone had success in repairing this kind of 
 thing? 
  The pickup roller is supposed to have a flat spot in it...if that's
what you're noticing, it's normal.

...
  The printouts have black in the wrong places
sometimes;
 fused, but -- well, basically it looks like a bad photocopy :)
 Sometimes the misplaced ink will have an imprint from another
 part of the same page, or from the previous page.

 There are also "splotches" of white here and there in the 
 good printouts where there should be some toner.

 I imagine something may be dirty, but not knowing a lot about
 laser printers (aside from keep away from the fuser when it's
 operating...), I don't' know where to start looking, nor would
 I necessarily know how to clean things up if I found the right
 spot. 
  CX and SX engines sometimes have problems with crap collecting on the
corona wires...especially the transfer corona underneath the paper
path.  Look for a trough about 0.5" wide with a hair-thin wire running
through the middle of it, possibly shielded with a sparse wrapping of
a plastic thread that looks like fishing line.  Clean this VERY
carefully by rubbing an alcohol-saturated cotton swap back and forth
over it.  That might help a bit.  If not, it may be the drum precharge
corona wire, which is inside the toner cartridge.  There should be a
little green plastic tool with a strangely-shaped felt tip stuck into
a clip inside the printer.  Stick this into the transfer corona wire
access slot on the toner cartridge and run it back and forth.  It's
self-aligning due to the shape of the green plastic tool and grooves
in the toner cartridge...there's only one place and direction in which
it'll fit correctly.  (sorry for the lack of detail here, this is
difficult to describe textually)

  Give that a shot and see how things clean up.  If that doesn't help,
contact me and I'll see if I can dig up anything else from my dusty
memories Canon CX and SX print engine repair training back in 1987.

          -Dave

-- 
Dave McGuire                                 "Mmmm.  Big."
St. Petersburg, FL                                -Den