just gotta love the tricks these marketing moguls use to extract our money
from our wallets.
they are not concerened with conservation, re-use or longevity. they only
seek to enrich themselves by selling us time limited and sales strategic
devices that require extreme cost to service or replenish. the initial
purchase is a come-on
the HP deskjet cartridge, (yes that tiny little ink thing) has probably
generated more profit for HP than most all its gear combined.
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.
It should be okay to snip off the mounting tabs with tinsnips or
whatever.
That's correct, the original part is rated at 150c.
You mean 315F/157c. ;)
No, that should be correct. The thermoswitch is intended to trip if
the temperature exceeds the working temperature. The original part
specifies the working temperature, but the Stancor part specifies the
trip temperature.
--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
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
Ed
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. :-)
Ed
If you are in the US or Canada call Premier Parts -
Phone: 800-668-8778 or Fax: 800-668-8037
They are the Samsung dealer.
The rating for the thermo-fuse is rated in Celius so it is 150C.
I've got quite a few Samsung printers I use for parts so I'll look
and see if I have a fuser or the thermister/thermo-fuse.
SparkyGuy wrote:
150c thermal safety fuse. They're usually a single-shot unit, like a
normal fuse, & must be replaced if they fail. If it fails, you need to
find out why the fusing assembly is overheating in the first place.
The most common cause is gunk building up on the thermistor used to
sense the temperature on the hot roller. Look for a thin cable running
to a small module pressed against the hot roller, situated under a
cover. The module will have a heat-proof, non-stick film over it that
is probably covered in cooked toner/dust. The film is quite easy to
tear/cut, so scrape off the gunk with omething wooden or plastic.
Before reassembling, make sure that the module is pressing firmly
against the hot roller. It's also a good idea to check that the
thermister is working correctly: connect an ohmmeter across the
connector & verify that the resistance changes when you heat the
module with hair-dryer. Alternatively, press the sensor against a cup
of boiling water. Do not try to test the thermistor with a flame or
soldering iron, or you will likely damage the internal connections.
--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
I found most of what you say to be so.
I disassembled the "fuse" and it turns out to be a single pair of contacts
with a bi-metallic dome (think kid's "cricket" sound toy that you pressed
with your thumb) that opens the contacts. When it cools, the contacts are
supposed to close again. Mine didn't seem to do that.
You're right: there was a buildup of gunk (toner) under the thin teflon (or
whatever) strip that separated the thermistor from the roller. Cleaned that
up with a blast of canned air. Luckily it wasn't sticky at all.
I put the thermal switch back together and installed it All seems to work OK
but I won't put the printer into service until I replace the switch.
Where would you look for one?
Thanks.
Anybody know how do dial down the toner use on this printer? The white space
on the pages seems to be a bit gray, and the build-up of toner under the
thermistor also suggests a slightly "rich mixture".
If it was easy to remove the controller board (or just have access to it) I'd
probably do a little exploring. But the pan that holds the controller PCB is
basically the frame for all the plastic bits to bolt to. It's akin to the
heater core in a car. It is suspected that the heater core is the first part
placed on the assembly line, and the rest of the car is built around it.
Thanks.
It depends very much on the engine model. Look for a green plastic
dial somewhere in the guts (EHT controller assembly, specifically) of
the printer. It should be visible with the lid open, but without
needing to remove any screws. If your printer has an LCD on the
control panel, there should also be a density setting somewhere in the
configuration menu.
OTOH, see below:
Is the grey on the blank areas consistant in density, or does it
contain very faint ghost images of the previous page? If the latter,
you have a problem with the drum-cleaning system, which is often due
to a bad cartridge. If you're getting streaks down the page, you
likely have dirty corona (high voltage) wires, that're preventing the
drum from getting an even charge across its full width. Another
possibity is dirt/dust bunnies in the window between the
laser-scanning unit & the slot on the top of the toner cartridge. It's
safe to dust out the window & mirror with a clean, dry paintbrush.
That's not the part you need to be looking at anyway. (And on the
bigger laser engines, you access the controller boards from underneath
the printer, not from the top.)
--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
engines used in most of the big brandname printers). I used to rebuild
& recondition about half a dozen fuser assemblies a week, so I still
remember most of the details. ;)
Good question. When I worked for Canon, we just ordered them from the
spare parts department, but you should be able to find them at laser
spare parts companies that cater for (any of) HP, Apple, Brother &
Canon laser printers.
On the part itself, you should be able to find a Canon part number,
which would be formatted something like: "RG?-????-???". Googling for
that part number (leave off the last '-???' part) should turn up
something. Don't pay more than $10.
Per Ed's earlier post, this looks like a suitable substitute:
<http://www.mouser.com/search/refine.aspx?Ntt €2-STO-325>
(It's a shame I tossed my laser printer junk box the last time I moved
house, or I could probably could've given you one.)
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. The standard method is to bend the mounting bars on the
thermoswitch so that it doesn't quite touch the roller.
My pleasure, I'm glad I could help.
--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
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. ;)
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.)
My pleasure. It's nice to know that my hard-earned experience with
laser engines isn't just wasting space in my brain. ;^)
--
W "Some people are alive only because it is illegal to kill them."
. | ,. w ,
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.
Ed
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.