HP CM1312 Printer

I posted about this before but it got back burnered. I ran out of black ton er and the thing quit working. I was reluctant to buy a toner cartridge bec ause I suspected something had gone wrong with the printer. I was right. Th e black did start to fade away of course, but one day it just wouldn't prin t anything at all in any color. All the sudden like.

Recently I acquired a junk printer the same model. I was told it needs a fu ser which is quite expensive. After taking it apart (violently) I can see w hy. Yes I animaled it a bit because I don't have all month.

Anyway, in my opinion, not enough paper has been run through mine to think the fuser is even worn out. I never eve put toner in it.

It was not in the best of environments for a time. A small area full of peo ple smoking cigerettes among other things, and generally not air conditione d in the summer, and gas (gravity) heat in the winter. I suspected high vol tage problems.

If mine needs a fuser or any major mechanical thing it is getting thrown ou t. I see how this thing is put together and they certainly don't make it ea sy to take apart. I will say that it is prety nifty engineering really. I w on't say impressive but not being familiar with this type of equipment I ca n appreciate the design.

On one side is a board with the HV supply, they use jumper wires on the com ponent side to make contact with spring things that conduct all the way to the toner cartridges which have the rollers built in. So far so good. That is the part I am going to get into first on mine.

At this point I wonder what kind of voltages I should expect. Of course mor e than zero but how much ? Couple hundred, couple thousand ? I can't see it being over about 2 KV because it doesn't appear to be made for any higher. If I see 700 volts there I would have no idea if that is low or what at th is point so that is one piece of information I would like.

Unless I find that something was spilled on the board, and I lack HV which I suspect, it seems quite possible that one of the cartridges might be shor ted. Of course I do not expect this to show up on an ohmmeter....

If anyone has worked on these I would appreciate anything. If I wanted to e liminate the toners as a short, how would I go about faking the machine out to make it run with them removed ? I might have a way, almost....

The junk machine had one toner missing. I already put the black in mine and tried it. It reads full up which brings me to another question. I wonder h ow it tells the level.

From what I've gathered, printers now do not need to weigh the toner or det ect the level of ink in an inkjet, they can approximate it very closely by just what has been printed. Apparently this causes a problem when one refil ls his own. As such they sell a replacement chip for the cartridge that sup posedly fools the machine into working.

Having thought about the matter, this could work several different ways. Of course the data could be burned into the chip, but it could also be stored in the machine in NVRAM and the chip on the toner is simply a serial numbe r. This would work just fine unless people started swapping toners. Would H P go to the trouble of doing it the harder way ? (well, more expensive by P ENNIES !)

The vendors of the replacement chips state that your printer must be workin g well at the time of replacement for it to work, after that you just fill the tank when the need arises.

The question therefore is; the toner I put in from the donor machine reqds full, does that mean it's full or is the machine just assuming it is new an d starting its countdown ?

I will be tearing into the machine I want to save in the next couple days. I would like some ideas about what kind of voltages to expect and so forth. Anything help[ful is appreciated, and if I (we) get this thing running the re might be some beer in it for someone....

Thanks in advance.

Reply to
jurb6006
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toner level sensing is usually by a sort of inductive proximity detector, the toner (or not) changes the Q of a resonant circuit

Reply to
N_Cook

detector, the toner (or not) changes the Q of a resonant circuit "

The chip is cheaper.

Anyway I now found I was measuring the wrong place. I need to drag it out a gain and check for the HV, which I STILL don't know what should be. The dif ference now is I know where.

If that proves good, I assume I would have to have a look into the fuser. U ugh, it better not be that. I don't hasve one and even if I did I would ref use, it is too much work for this unit. Five hundred new, on in pristeen co ndition froth with toners might fetch half that. The fuser is $190. If I st ole one I would not put forth the effort to change it. (we clear on that ? lol) It would take too much time, really.

Actually f*ck it for now. I only came in for a trim on my left front paw so I oculd play some guitar.

Reply to
jurb6006

If the fuser heating element has failed, you will get a perfect-looking page out, but the toner will rub off the paper when you touch it. if the paper comes out blank, then the toner is probably not transferring from the toner bar to the paper. First, the photoconductor is charged and the image is written by laser on the photoconductor, creating the image as charged and non-charged regions. The toner jumps to the charged regions, then is transferred by the opposite charge to the paper. It could also be a failed laser or laser driver.

Jon

Reply to
Jon Elson

Thanks. I kinda started thinking like that. Trying to be a printer technici an. I have determined that fuser is good.

The parts unit seems to have taken on moisture, perhaps cat uriine as he sa id he has three cats. Toward the bottom is what I think is called the trans fer plate, on his there is toner all over the place and the rollers on the cartridges have all kinds of lines in them.

I actually got the manual for the thing, surprisingly.

formatting link

I know it has the word "store" in the URL but I got it for free. You might want to bookmark that.

As a test I again ran the color copy mode, it actually did print but very f aintly. The paper was slightly warm, I would guess from the fuser. The litt le bit of toner on the page was stuck well, it did not smudge.

According to the maual there are like 13 HV power supplies. These things ha ve come some way since I familiarized myself with the process.

Anyway, in my current opinion, one of the HV sources is out. There is a sli ght possibility that the LASER is bad and only putting out a fraction of it 's power but it seems to me that the HV is more likely to fail. It doesn't matter though because I have the whole HV board as well as the LASER assemb ly.

Replacing either as a whole would require alot more disassembly so I would really prefer to just replace a couple of components on the HV board.

Is there a surefire way to confirm the output of the LASER ? One reason I a sk is that they don't seem to give alot of detail on these HV supplies, lik e how much do they put out. Towards the bottom of the board where the secti on is that (I think) charges the drums I see disc caps rated at 6 KV.

At this point when I tear into it again, (hopefully after sage advice from here...) I figure I'll take a wild guess that they didn't uase 6KV caps for a 5 volt line, that it is definitely over 2 KV. Unfortunately I have no HV probe, but I'll figure out how to measure it. I might have to go digging t hrough my old big resistor stash.

What would really help is a way to confirm the operation of the LASER. The other thing I would like to know, and yes I wil RTFM some more to see if it is in there, is there just one LASER and a bunch of mirrors or are there f our LASERs ? It almost seems there should be four because to only use one w ould be an engineer's nightmare. If there are indeed four LASERs it is high ly unlikely that all four of them to take a shit at once which leaves the p ower supplying them. Doesn't aseem to be much there, one plug with four or five wires, and a ribbon cable. I would gues the ribbon cable supplies the data in something like an LVDS format and the other plug is power. That is accesible from where I'm at, but the thing is I am going to have to comb th at manual for info on the pinouts. Last time I was trying to understand why the hell there are 13 HV supplies in there. It's starting to make some sen se but I can indulge in more studies of the theory of operation (and the un iverse) after the thing works. I don't need the parts from it all over the place for ten years.....LOL, I have enough things like that.

So really, confirming LASER operation, perhaps I could smear lemon juice on a sheet of paper or something like that ? BELIEVE ME I am not going to try it without someone saying I should. I don't want to wreck those rollers an d all that by sticking anything on there it won't like.

Reply to
jurb6006

"The fuser is

We are NOT clear on that. What I thought was the fuser panel, from what the guy said, is actually the transfer panel I think. The fuser is not all that hard to change. The transfer panel is what is smack dab in the middle of everything.

Reply to
jurb6006

It seems to have been the LASER. I changed th HV board - nothing. then of course I forgot to rehook this little spring thing to the LASER assembly and it wouldn't work.

Now comes the fun part, putting it all back together.

So, on the by and by here - are these manufacturers allergic to screws ? Everything clicks together in this thing.

Reply to
jurb6006

OK, it survived the operation. Now I have to find out how to do the registration because it is awful.

Also I would like to hack a wireless MODEM/router to connect the thing to the house network, but one thing at a time.

Anyone got any ideas how to set the registration on this thing or should I just start pressing buttons and/or go through the software ?

Reply to
jurb6006

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