Jeff Liebermann wrote:
On Tue, 21 Jul 2009 17:57:15 +1000, Bob Larter
wrote:

Jeff Liebermann wrote:
I do some HP LaserJet printer repairs. The older models (LJII, LJIII
and LJ4) required some grease on the drive gears and a few metal gears
on shafts. When needed, I used lithium white auto grease, which is
probably not the right stuff, but worked well.
White lithium grease is fine for those parts. That's what Canon use
themselves for that purpose.

Thanks. I wasn't sure it was the right stuff.

However, all the other
nylon gears were self lubricating. The best way to make a huge mess
was to lube all the gears. I'm not 100.0% sure, but I believe that
current HP printers (LJ42xx, 43xx, etc) do not require any
lubrication. I sometimes use "rubber restorer" on the paper feed
rollers, but only if the paper is slipping and I don't have a
replacement roller or foot.
I use acetone (or nail-polish remover) to take the 'shine' off paper
rollers, which gives you years more life out of them. It's also good for
the separation pad in the paper pickup assembly for laser printers & the
document pickup assembly in faxes.

Nope. I've had problems with acetone warping the plastic spindle
under the rubber feed rollers. It works, but is far too strong a
solvent.

If you're warping the spindle, you're using too much acetone. Dip a
coarse rag in the acetone, & rub the roller with it. You do need to be
careful to keep it away from the plastic.

If the rubber is impregnated with oil (to keep it soft), the
acetone will dry it out, causing the rubber surface to get hard after
about a month or two of use.

That's never been a problem for me. I've serviced a heap of printers
under service contracts, & never had any of these fixes come back to
haunt me.

I switched to a xylene based solvent:
http://www.fixyourownprinter.com/specials/misc/chemicals/S03
which doesn't have the problem. One problem is that it's a really
foul smelling cleaner. I have to do the cleaning outdoors, and store
the can inside two zip lock bags. I threw some towel paper with some
of the stuff on it, and it stunk up the office for days.

There are also some nasty health effects for Xylene,

You're not kidding. No way would I go near that ****. I'll stick with
acetone, thanks all the same.


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