On Wed, 07 Mar 2007 20:53:46 GMT, ehsjr <ehsjr@bellatlantic.net
wrote:


SparkyGuy wrote:

Fuser quit working on my laser printer. Removed the fuser and found that the
snap-action bimetallic thermostatic switch for the fuser heating element is
open-circuit. I removed it from the fuser and pried it open. Looks brand new.
Reassembled it and it now conducts. Then it opened again. Not reliable enough
to reinstall due to critical job it does. It rides against the cool roller
(not the heated one) and cycles the heating element so as to keep the
temperature constant.

Markings on front:
PW-2N
5214
E150

I am *guessing* that the E150 indicates the temperature.
Take a look at Mouser part # 802-STO-160 to see if
it will work for you. It is normally closed, and
opens when the emperature rises above 155 to 165 F


The temperature is rated in degrees C, not F, but other than that, it
looks like you have the righ part.

Lionel wrote:
The temperature is rated in degrees C, not F, but other than that, it
looks like you have the righ part.

Mouser gives the ratings in both F and C. If he needs 150 C
then the part I posted is wrong. The closest part # would be
802-ST0-335 which is rated 315-335 F, 157-169 C

On Fri, 09 Mar 2007 03:28:22 GMT, SparkyGuy <SparkyGuy@mumcrank.ck
wrote:


Make sure you're very careful about comparing the replacement part to
the original, & in how you mount it. If the original had yellow/orange
film (anti-stick) over it, you'll need to come up with some way of
mounting the new thermoswicth so that it doesn't rub on the roller, or
it'll scrape off the teflon coating, which will leave streaks on your
printouts.

It seems that the thermo shut-off is positioned in close proximity to -- but
not touching -- the heated roller. It's designed to open when the temperature
(within about 1/8 inch of the roller) reaches 150c.


Close, but not quite correct. It's designed for a hot roller operating
temperature of 150c, & opens if it goes significantly higher than
that. ;)


The standard method is to bend the mounting bars on the
thermoswitch so that it doesn't quite touch the roller.

Yeah, that's how it is in this one.


Good. That version of the design is easier to fix than the version
where the thermal cutout touches the roller, which used a special
cutout that had an indentation in it that matched the shape of the
roller. (We fixed the older version by bending the tabs on a standard
cutout so that they match the roller distance of the newer type.)


Thanks.


My pleasure. It's nice to know that my hard-earned experience with
laser engines isn't just wasting space in my brain. ;^)

On Fri, 09 Mar 2007 06:03:48 GMT, ehsjr <ehsjr@bellatlantic.net
wrote:


Lionel wrote:

The temperature is rated in degrees C, not F, but other than that, it
looks like you have the righ part.

Mouser gives the ratings in both F and C. If he needs 150 C
then the part I posted is wrong. The closest part # would be
802-ST0-335 which is rated 315-335 F, 157-169 C


Yep, that's the one I suggested after reading your post. ;)

Thanks! Glad you picked up on the error. It would be a bummer

Thanks! Glad you picked up on the error. It would be a bummer
if he put in the wrong part, to say the least. And I've enjoyed
reading & learning from your posts on this.

Lionel wrote:
My pleasure. It's nice to know that my hard-earned experience with
laser engines isn't just wasting space in my brain. ;^)


Not wasted - it is very interesting!

I take it that
most of the time this type of failure is caused by
the build up of crud in there? Is it a fool's errand
to try to do preventive maintenance - maybe just as
likely to cause a problem as to prevent it?

Also,
when these printers start "smudging" the non-printed
area, is that a sign of impending toner replacement?

The prior printer did that for a long while before
the printing became light & toner needed replacement.
I tried to clean it on a number of occasions, but was
not successful in clearing the problem. So either
I wasn't cleaning the right things, or it wasn't an
issue of cleaning.

I'd offer to send the OP a thermostat, but it's clearly a
different printer (this one reads the hot roller)

and there are no
visible markings on it at all (I have not fully disassembled the fuser
assembly to see if there are any on the backside of it, but the visible
parts have no markings)

On Fri, 09 Mar 2007 06:24:08 GMT, ehsjr <ehsjr@bellatlantic.net
wrote:


Lionel wrote:

My pleasure. It's nice to know that my hard-earned experience with
laser engines isn't just wasting space in my brain. ;^)


Not wasted - it is very interesting!


Thanks. :)


I take it that
most of the time this type of failure is caused by
the build up of crud in there? Is it a fool's errand
to try to do preventive maintenance - maybe just as
likely to cause a problem as to prevent it?


Not if you know what you're doing, but it's enough of a pain to get at
the relevant part of the fuser that I've never bothered doing it
unless I run into symptoms like the OP's, or am opening up the printer
for some other reason, in which case I'll give it a clean up while I'm
in there.
BTW, a tiny squirt of silicon spray on the woolly, removable wiper on
top of the hot roller for every ream of paper you put through the
printer will greatly extend the life of the teflon coating on the hot
roller, which is hard to obtain, & a pain to replace. It's also good
to clean the accumulated gunk of the separation claws (that 'scrape'
the paper off the hot roller in its way out), because they're prone to
causing paper jams on exit, & can scratch gouges in the teflon
hot-roller coating.


Also,
when these printers start "smudging" the non-printed
area, is that a sign of impending toner replacement?


It totally depends on the cause, of which there several for that
particular symptom. (And there are unrelated problems that cause
symptoms that look very similar to the inexperienced.) But yes, the
most common cause of dirty backgrounds is a cartridge on its last
legs. At a site where they have more than one printer of the same
type, the easiest, quickest way to detect a bad cartridge is to swap
cartridges with another unit, then do a test print from both.


The prior printer did that for a long while before
the printing became light & toner needed replacement.
I tried to clean it on a number of occasions, but was
not successful in clearing the problem. So either
I wasn't cleaning the right things, or it wasn't an
issue of cleaning.


Most likely the latter. If it came good when you put in the new
cartridge, you've got the answer to your question. ;)

SparkyGuy wrote:
ehsjr sez:


I am *guessing* that the E150 indicates the temperature.
Take a look at Mouser part # 802-STO-160 to see if
it will work for you. It is normally closed, and
opens when the emperature rises above 155 to 165 F

Ed


Thanks for your comments, Ed. I saw that one but would like to find a
direct
replacement without having to hack off tabs, etc (original has no
separate
mounting tabs; the connection tabs are use for screw mounting also).

Also, fuser assembly gets up to high 300f+ so I, too, am guessing at the
temp
rating. 150f seems a bit low for being in such proximity to the headed
roller
(few tenths of an inch). Maybe it's 150c (302f)? It *is* a Japanese
printer...

The nearest Stancor product is 157f (315c)... too high?


I dunno - but I can commiserate with your situation.
When my toner ran low, I went to Staples to buy a
replacement. 70 dollars! But, serendipity - they had
an entire printer (Brother HL-2040) on sale for $110,
and it's faster and better than the old one. (The price
has dropped on them since I bought, so they are now
$120 not on sale.) Anyway, it worked out well for me,
but $70 for the toner still rankles! Interesting
psychology - I didn't spend $70 and if I had I'd
still be unhappy about it. I spent $110 - $40 more,
and I'm pleased as punch. And it's actually more than
$40 extra when you add in the tax.

Maybe the people who set the prices have an ulterior
motive? (How do you make a "frowny face" icon with
smoke coming out of its ears?)

Ed

no one in business for profit ever cares about resource depletion
until their own kids die from it.. & even then, they figure they will
leave THAT problem for their kids to solve. "if it aint broke,doan
figz it"

if resources become low
enough to make a majority of people start to begrudge this and DO
something about the way they choose to spend their money, it will
carry on.

hapticz@sbcglobal.net> wrote in
news:8NpLh.1277$rj1.718@newssvr23.news.prodigy.net:

no one in business for profit ever cares about resource depletion
until their own kids die from it.. & even then, they figure they will
leave THAT problem for their kids to solve. "if it aint broke,doan
figz it"


Don't kid yourself. They don't think of it AT ALL. Period. There are two
ways to think things like this, unless you're no longer sane, in which
case
all bets are off:
1. You assume it IS relevent to you, and all that you care about, in which
case it nags at you till you eventually do something, ANYTHING, to appease
the nagging sense of doubt, in order to make yourself feel more secure. OR
2. You assume your security is ALREADY assured, thus you don't think of
doing anything to change what others appear to be whinging about as a
perceived threat.

Given that the firms doing this ARE amongst the most secure, financially,
politically, and socially, their arrogance is the cause. This is not mere
ignorance, it is WILLFUL ignorance, the worst and most dangerous kind. It
also the kind that is hardest to forgive, and if resources become low
enough to make a majority of people start to begrudge this and DO
something
about the way they choose to spend their money, it will carry on. There
are
firms that will sell cheap refills, but these aren't the cure, they DEPEND
on the problem to exist.

Now, as I'm saying my small rant in the presence of electronics engineers,
some of which are considering their own business management as well as
electronics details, I won't try to tell them solutions they probably know
more about themselves, it's enough to point out tht there will be a market
for products that don't fleece the buying public at unacceptable expense.

I do have one small suggestion, I guess. Innovation is the ONLY way a
small
firm can get ahead. After all, it;s buying up innovators that makes the
big
firms get ahead, right? So, if small firms patent their stuff precisely
instead of in the aggressive way large firms do to try to stop others,
instead of just protecting themselves, this can help, it can prevent a
large firm from muying and burying innovation that threatens their own
wasteful empires, and it can also prevent them from revising history to
try
to force their exploitation of your ideas. Patent it under your own name
if
you invent it. A firm can't claim your idea even if you thought it up on
their time! Do they OWN your mind? I think not. At least copyright it by
sending yourself signed sealed copies. Do this before it becomes valuable
to someone else.

There may be all kinds of better ideas to erode the tech society that
wastes so heavily, but I'm not inside it enough to think of much more than
I have said here.

big companies/small individuals practice the same ignorance toward life,
short term perspective long term dreams.

future/past, we all gonna die anyway, so grab while u can??