Phaser 780--stopped printing on paper

[larry314]

I have a Phaser 780, and everything on it acts normal--no error messages, etc. It processes a sheet through it ok, but nothing prints on the paper. Also the start-up test page comes out blank. It had been working just fine, but all of a sudden this is happening.

 

[marty5261]

Run a print job then stop it on any cycle just by opening a door. This is a 4 pass printer so if you stop it you should see and image on the drum and accumulator belt. Just pull the IU out and check it out, if either has an image on it then soulds like an accumulator cleaning belt assy or teh transfer roller clutch, though usually the latter will display an error 24. Hope this helps.

 

[CULTOFLON]

There are two places I would check, I've seen these on this machine. One is remove the imageing unit and check for paper in the path of the laser (most common) the second one had me stratching my head for awhile, paper around the 2nd bias roller, you will have to remove the fuser tray and cleaning unit to get to the 2nd bias roller. When you reinstall the cleaning unit it must be free (move back and forth freely). If it is not all you will get is black print. Later

 

[larry314]

Thanks for responding. I ran a print job and stopped the printer during the print cycle and there was no image in the imaging unit drum or the accumulator.I also looked for paper in the laser path and wrapped around the second bias roller and did not find anything.
So I am hoping for further ideas.
Regards,
Larry

 

[larry314]

I removed and reinstalled the cleaning unit to look at the 2nd bias roller and when I put it back together and tried It it printed on 1/2 the sheet the print near the center of the sheet is smeared and the rest of area that printed looked normal. The 1/2 of the sheet that did not print was totally blank.
Can anyone give me some direction from here?
Thanks,
Larry

 

[larry314]

I am still working on the problem described above. A person sent me some troubleshooting pdf sheets that indicate I should make an engine only test print.The sheet says if the machine makes the engine only test print to replace the image processor board. How do I print an engine only test print?

 

[CULTOFLON]

Just to make sure the cleaning unit is installed correctly loosen the two screws in the front of the machine and make sure the cleaning unit moves freely, sometimes just loosening and retighting the screws works. Later

 

[larry314]

Hi Cultonflon -
Did it several times.
No go

 

[larry314]

Thanks for all the help -
I am still working on this machine.
Still blank prints.
I replaced the hi voltage power supply board and the laser source. No go. Still no image on the drum or accumulator belt.
I bought a unit for parts and am using it to attemt to fix this machine. The unit I got has a bad engine control board so I cannot use it. In trouble shooting I am at the point that calls for replacing the accumulator belt.I have the spare unit tore down pertty far and still see no way to get the accumulator belt out. Is there a quick easy way to do this?
Also are there any voltage ckecks I can do to check for problems?

 

[jdwvw]

The only EASY way I know of would be using a C4 repair kit.

The Belt comes out the top. You have to remove the main drive asm as well. It is not an easy task.

You may try pulling the out the paper feed unit on the right hand side and look at the top plate. It could be bent up causing it to rub against the accumulator belt.

 

[larry314]

Thanks for the advise jd- I did not see any problem with the paper feed unit. Any other ideas?

 

[larry314]

Hi all - Well I got it tore down and replaced the accumulater belt. The unit I installed squeaks when it runs so that may be an indication of a problem.
In any event I am now getting a partial image. It appears smeared and about 1/2 there. I Swapped out the imaging unit to see if it made a difference ( no change ).
So, at this point it would seem to me that my accumulator belt was bad and the used replacement I installed is bad as well. Any thougths?

 

[larry314]

I tried printing colors and just got smeared images.
I tried printing just black and found that I can print black with normal quality. Still cannot print color.
Any suggestions?

 

[CULTOFLON]

If you can print black but not color it sounds like either the cleaning unit has a problem or the clutch on the fuser tray that lifts the cleanin unit is not working. Later

 

[larry314]

I checked the cleaning unit and found it was binding. I freed it by loosening the bottom screw on the part that holds it in. I then tried printing. At first got a blank sheet but as I contiuned printing I got more and more of the image. After about 10 sheets I had an image covering about 12 the sheet in the center. It had all colors but was a smeared image.
Any ideas?