print quality w/ 740

[garion911]

Hi there. I have a 740 I got off of ebay..

When I print, it seems that the toner isn't transfering to the paper. I caused a jam at C, removed the paper, and appear similar to the example below..

I have replaced the imager, main charge grid, and transfer kit to no avail. Paper is 20lb Xerox-brand (4024 premium paper). Fuser seems to be ok.

Could it be the transfer kit not pressing hard enough against the imager roller?

Here's a link to the startup page printout as a good example of whats happening:

http://garion.tzo.com/printer1.jpg

On the single color print out, there doesn't seem to be a pattern to the white splotches.

Welcoming any ideas......

--John

 

[garion911]

Never mind.. I figured out what it was..

The transfer roller was not making contact to electrical peice that it was supposed to.

I bent tab out, and poof.. Working printer.

Whew.

--John

 

[iyedidit]

Hello garion911,
I am experiencing a similar problem with a Tektronix 740 printer. If possible can you please explain what you did in more detail? I've been struggling with this thing for a month! Thanks

 

[garion911]

(from memory, printer is at home, currently at work..)

Pull out the paper feeder..

Look into the printer where the paper feeder lives, on the left side you should see a black peice of plastic hanging down. It has 2 metal tabs on it. These metal tabs make contact with the rollers in the paper feeder (look at the paper feeder, and you'll see 2 rollers (one being the transfer roller) with metal sticking out.

When i looked at the metal tabs, they were covered in toner.. I cleaned them up, and I also bent the tabs outward to make contact with the rollers..

Hope that helps!

 

[iyedidit]

Thanks for the quick reply!
I located the tabs you mentioned. They were covered in toner. Cleaned em up and bent the tabs outward. Removed the imaging unit so I could get a better look at the paper feeder reaching the contacts, put it back in and printed out a couple test pages. The print outs continue to be poor quality. My print outs are no where as bad as the one you posted but they are definately not solid. The odd thing is when I print out the solid color test pages they look great, but text or other images have white splotches. Personally I can deal with it, but its main job is to print out labels and the the quality just isn't there. I've noticed the problem after replacing the clutch: second transfer roller to correct an error 33(a thread on this webpage "tektronix phaser 740 transfer kit error&quot. All other user replaceable parts have been replaced on this unit (with the exception of the transfer kit), some twice. any other suggestions? Thanks again for your help!

 

[garion911]

Heh.. I work in front of my computer all day... Its easy to do quick responses..

Well, I've only had the printer a couple weeks, and this being my first time playing with any laser, its all trial and error..

Probably what I would do is (and its definitly NOT a standard procedure.. I am not responsible for any damage to you or your equipment..) cause a "jam at C" error.. Thats how I figured out it was not the fuser in my case.. Here's how I did it.. I opened the front door, and placed a screwdriver into the sensor that detects if the door is open.. I then printed something, and when I could see the paper going into the fuser, I used another screwdriver to push the paper up, causing it to not go into the fuser, a "jam at C" results.. Then I pulled the paper out and looked at it.. Be warned that the toner is still loose and will get on your hands and smear.. If you see the white sploitches, then its before the fuser.. If it looks ok, then its probably the fuser and/or roller and/or cleaning pad..

If its before the fuser, another possible area to check is the contacts to the toner carts themselves.. Don't recall where they are, but my guess is the right side (looking into the printer)...

Good luck...

 

[iyedidit]

Well the blotching is definately happening before it reaches the fuser so we can eliminate that. I would like to think the toner cartridges are ok, since they have been replaced twice since this started happening. The imaging unit was replaced as well. I'm still at it, cleaned off all the contacts I could find on the thing. more suggestions? Your help has been greatly appreciated.

 

[garion911]

Hmm... I don't really know.. If your solid color printouts are ok, but the text/images are not, then I don't know.. I was having my problem on all pages..

Do you have your transfer-kit type set correctly??

Maybe its the lens stuff? When you take out the imager (covering it to make sure it isn't exposed to light, that will ruin them), and you look in, there's a set of red LED's in clear plastic (no clue what they do..).. Clean the plastic off.. (at least I did..Those LED must do something .. Then inside the imager area, on the top, there's a long slit.. Thats where the "laser" draws the images.. I would clean that with a can of compressed air or something..

Though if you noticed this after you replaced the clutch thingy, then thats probably where the problem lies..

Needless to say, take all my advice with a grain of salt.. I'm picking all this up as I go along (reading howthingswork.com on laser printers helped!)..

 

[iyedidit]

Well, I think I found the problem. I was able to get access to another 740 printer so I swapped all the parts I could think of. Print quality improved greatly when I replaced the Black Toner. Now the end user of this printer claims to have replaced the toner in the unit a couple of times. When I swapped toner, the unit that worked fine started to print bad and the unit that was printing bad worked fine. I returned the printer and he had another black toner cartridge, brand new, installed it and the print was faded again. is it possible that he purchased a bad batch (at least 2-3) of black toner?