I'm looking for help with my brother MFC-8300 multi-function machine
(laser printer, copier and fax combined). I have had it for about five
years, and use it in a home office for my full-time job. It does not
get heavy use, but probably prints a few pages a day.
 
The problem is that the toner cartridge claims to be empty when it
cannot possibly be. I have asked Brother for help, but they give a
stock answer about cleaning the corona wire and shaking the toner.
This works as a very temporary fix, and it will usually allow me to
print a few pages before going to the "toner empty" message, and it
seems to be getting worse. When it does print, the quality is
absolutely fine and not at all light. I have purchased the "official"
Brother toner each time (most recently, the high capacity version with
about a 6000 page limit). When I replaced the  first toner cartridge
to become "empty" long before it's time, I thought maybe I had a
faulty toner unit and got another. But when the next one started the
same thing, I thought there must be a problem with the printer itself.
 
The authorized dealer is at least an hour's drive away, and their
hourly rate is expensive. I feel sure the information on servicing it
or fixing it must be out there somewhere so I can fix it myself, but I
just can't find it. I also know that I could get a fairly inexpensive
replacement laser printer, but I just hate to chuck this machine. I'd
like to know if this problem of getting a "toner empty" message
prematurely is a known issue that I can fix myself.

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Request for Question Clarification by cynthia-ga on 18 Feb 2006 21:05 PST

There's an FAQ page at the Brother web site that addresses how to
[possibly] solve this:

MFC8300/8600 - Q.  Why does the display read "TONER EMPTY" after minimal use?  
http://www.brother.com/usa/fax/faq/zl/faq_zl.htm

Please try this, and let me know if it works for you. If it does, I'd
like to post it in the answer box..

~~Cynthia

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Clarification of Question by bookruth-ga on 22 Feb 2006 09:14 PST

Thanks, but alas no. I have done this a few times, and this also the
solutionr Brother offered via email. It does work as a temporary
measure, but the problem returns after a few pages of printing. It
says if this doesn't solve the problem that I need new toner. The
toner is fairly new and far from empty. If this doesn't seem to be a
known problem, I suppose it's possible I've had two bad toner
cartridges in a row and should just buy a third.

I'm no expert on Brother laser's but pretty good with HP's.  HP's
toner cartridge toner level monitoring system usually have a small
microchip that must monitor the impedence of the level of toner
inside.  I would look on your toner cartridges for an electrical
contact of some sort, and check where that mates up with your printer.
 I would clean those contacts inside the printer.

Also, you could try purchasing a toner cartridge from a different
vendor, you could be purchasing a supply from a chain that has old
toner that has been exposed to the elements, such as humidity or
constant temperature changes that could be causing the toner to clump
inside the cartridge and trick the toner measuring device.

Just a few thoughts.  Let me know what happens...

Steve

Steve,
Thanks very much for the advice. I gave the area where the toner fits
a good cleaning with alcohol, q-tips and compressed air and looked for
contacts. I saw something that may have been contacts, but they also
looked like they were just sensors to see if the toner was in there.
(Two little wire loops that pushed into back into the body of the
printer when pressed.) I cleaned them and anything else that could
possibly be a contact, and initially it went back to the "toner low"
(but not empty) before printing anything.

I took a closer look inside and saw what looked like a plastic lens
that lines up with a small round window into the toner cartridge. I
figured that may be a sensor of some kind, and cleaned it up too.
After that, the error message disappeared as soon as I turned it back
on, and I immediately attempted to print a 75 page document, and the
whole thing printed! (this is miraculous compared to my 2-4 pages
limit before). There is no error message now. I don't know if that was
the thing that did it or if I had cleaned something else already in
the process, but it did start working immediately after that lens was
cleaned.

I'll see if it sticks, but so far so good. Thanks very for your advice
on the contacts, it gave me direction and something to look for.
Ruth