[sci.electronics] Some Tips on Repairing Laser Printers

keithl@loop.uucp (Keith Lofstrom;;;628-3645) (10/15/90)

I have an Apple Laserwriter Plus, based on the Canon laser engine.
Asking Apple Service (an oxymoron) for service information is pointless,
but most of the things that go wrong will be in the Canon engine, which
is also used in the original HP Laserjet.  The mechanism shares many
mechanical parts with the Canon PC-25 copier.  Apple and Canon won't sell
you a manual, but HP will.  I have found the HP manual quite useful;  when
I need mechanical parts, I copy the page and take it down to a local copier
repair shop.  The copier is also compatable for trays and paper guides,
though there are some bumps on the side of the paper input trays that
may be different.  I have had no problems swapping letter and legal
paper trays between units.

I have not had to pay Apple's bloated service or parts prices yet.

I have had the fuser malfunction, due to inept reassembly after changing
the roller.  One of the things that can go wrong is a little 47 ohm
resistor on a plug inside the fuser controller.  This resistor acts
rather indirectly as a fuse, and sometimes needs replacing.  Remember;
your ohmmeter is your friend!  I don't know whether there are any subtle
differences in fuser lamps, but a copier lamp seems to be working fine.
Your mileage may vary.

I even buy my toner from Chenesko Products and do my own drill-and-fill.
I'm a cheap so-and-so.  OK so far.

Some brave soul with one of the newer laser printers might check for
similarities to current copiers, and post their findings.

-- 
Keith Lofstrom  keithl@loop.uucp ...!sun!nosun!loop!keithl (503)628-3645
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Power ICs

rrw@naucse.cse.nau.edu (Robert Wier) (10/21/90)

In article <1990Oct14.221825.26982@loop.uucp>, keithl@loop.uucp (Keith Lofstrom;;;628-3645) writes:
> I have an Apple Laserwriter Plus, based on the Canon laser engine.
> Asking Apple Service (an oxymoron) for service information is pointless,
> but most of the things that go wrong will be in the Canon engine, which
> is also used in the original HP Laserjet.  The mechanism shares many
> mechanical parts with the Canon PC-25 copier.  Apple and Canon won't sell
> you a manual, but HP will.  I have found the HP manual quite useful;  when

 This is indeed true.  We have a Laserwriter IINT which stripped a 
 gear after about 40,000 pages.  Apple wanted to do a complete
 print engine swap for $800.  Our electronic tech here noted that
 it was the same mechanism as in our HP LJIII, ordered the part from
 HP and installed it.  Total cost was something like $10.  

 Apple drives me crazy sometimes on these things (even being a
 Mac software developer...)


 - Bob Wier

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