WC 7328 lighter toward fron of copier

[axyun]

Customer called to say there was a message to change black imaging unit and boss installed incorrectly causing loud grinding sounds. When I got there the imaging unit was not an old unit . I removed from machine and replaced with new one. Noise was gone but prints/copies were lighter toward front side of machine. I thought maybe transfer belt had been affected so I removed but it looked intact. When I reinstalled the copies were okay.
Customer called back a few days later to say lighter at front side again. All colors. I'll check transfer roller and transfer belt again. I am bringing parts with me. Anything else I should be looking for? Frank/ActionPhotocopy

[xeroxsharp]

Re: WC 7328 lighter toward fron of copier

Somebody was very strong with xerographic release lever assembly.
1. Check drum railes.
2. Lift unit is misaligned. EDOC PL 5.1
You need to realign left and right lift assembly.
Lever assembly has marks on both sides ( REP 9.19 )

If you are lucky only 1/2 hour off work.

Good luck!

[axyun]

Re: WC 7328 lighter toward fron of copier

Thank you. I will check SM for the procedure as I have not done it before. Frank

[axyun]

Re: WC 7328 lighter toward fron of copier

I don't see the procedure in Phaser 7760 which has same setup with same drum units ,lift assembly etc. I have been unsuccessful in trying to buy WC7328 series service manual. Frank

[adriansto]

Re: WC 7328 lighter toward fron of copier

The service manual is in edoc format. Do you have pws software ?

[axyun]

Re: WC 7328 lighter toward fron of copier

No I don't. Not sure what i would need to do. I am surprised not in Phaser 7760 as virtually same . I want to be prepared to adjust the drum lift assembly allignment in case custome maY have messed it up in installing drum improperly. Frank

[adriansto]

Re: WC 7328 lighter toward fron of copier

You dont know how to read the sm. Go to chapter 4 on PH_7760 , repairs 9.x - Xerographics and read rep9.18 to 9.21 procedures.
Before make a lot of " adjustments " be sure you have same light band on IBT. If the image on IBT is good then the problem is 2nd BTR assy.

[axyun]

Re: WC 7328 lighter toward fron of copier

Customer was incorrect. The light copies toward front of machine are only on black and not with colors. I swapped drum unit but not change. The developer looked okay with good even coating on mag and no evidence of disturbance as from foreign matter in unit. The drum rail appeared to be same position as others. I used wand to clean laser but may have put in only half way as problem toward front of machine. I saw no evidence of any damage. Is it necessary to put wand all the way in as afterward i read that in manual.

The customer had said that the boss had probably put drum in incorrectly after a black drum change message. She said very loud grinding sound. I removed the drum without a problem and put new one in. The drum in there was not new. First took out transfer belt to see if any damage toward front and after i reinstalled the prints were okay. A few days later light again at front. Any help is appreciated as I am just learning machine with little experience. Frank

[axyun]

Re: WC 7328 lighter toward fron of copier

Thank you Mitja and Adi for trying to help. I appreciate that very much. I have not made any progress on this problem yet.

Would i be correct to assume this is not a transfer belt or transfer roller problem? The light prints toward front of printer are only happening with the black.
Also if the black toner was a little low or clogged would this affect the prints more toward front side of machine. I would think not as the developer unit would evenly disperse the toner as it turns.

It can't be the drum as i have exchanged the drum with another and still have same problem. The customer had said there was a very loud grinding sound after the boss removed the black drum and then reinstalled it. When I took it out it seemed to come out easily because i did not look carefully i am not sure if it was in incorrectly. I reinstalled it and there was no noise. Just light prints at 3 to 5 inches of page only with black.

I did not see any evidence of change in position of drum rail as i have to consider the possibility that the drum is not close enough to developer at front side of machine. I tried stopping copier on each of several copies i made so that i could check image on drum but was never able to see image on black drum. Is the transfer immediate. I wanted to see if the problem was in the image coming onto drum or transferring to belt .

I would not think that it should matter if I clean the laser without putting the cleaning wand in all the way as the problem is toward front of machine.

Is there a way for me to see the image on drum or is it immediately transferred to belt? Can I adjust the front side of drum rail up or down to see if it is causing drum to be not close enough to developer or belt at front side of machine?

The marks on the left and right lift units are aligned so that should not be the problem.

Also I forgot how to remove the finisher assembly(YFN1) without taking the knobs and screws. I thought there were rail screws to take out so that I could lift unit off rails.

Please tell me what you think from what i have just described. Frank

[adriansto]

Re: WC 7328 lighter toward fron of copier

I dont know what can I say. Try to print 10-15 black sheets in series, stop the machine and check image on drum. First print only black then try same thing with black from all colours.
The lighter side can be from drum to belt transfer or from developer assy. You even can check only to be sure if the light side dont appear on colors Y, M, C.
Also 2nd BTR can cause this but the defect appear no matter which colour is printing

[axyun]

Re: WC 7328 lighter toward fron of copier

Thank you Adi. It is only on black. I ran colors with a lot of solid areas and printed normally from top to bottom. Frank

[adriansto]

Re: WC 7328 lighter toward fron of copier

Check again the latch of the K drum - read again REP 9.18 from service manual to be sure there is all ok.
Sometimes light prints on black only came from bad K developer clutch. Check also this clutch.
Can you reproduce the defect on 11 x 17 paper size and post here the scanned image of the paper sheet with light band image quality defect ?

[axyun]

Re: WC 7328 lighter toward fron of copier

I don't have samples with me and won't be back to customer any earlier than tomorrow afternoon. If it were the developer clutch wouldn't that affect the whole image and not just lighten the bottom few inches. I will check the manual to see how to remove as I can always swap one developer clutch with another to test. Frank

[adriansto]

Re: WC 7328 lighter toward fron of copier

Yes you are right, bad clutch make light print on whole sheet of paper. But if the machine is tilted and the clutch make intermitent coupling the result can be the starved toner on one end of the dev assemblies.

[Scarecrow]

Re: WC 7328 lighter toward fron of copier

Check the trimmer bar on the dev housing - .020 I think. If you can't find the spec, make the lite end the same as the dark end - not the best way but it will work. High resistance in the drum bearings will suck the dev out and cause a light and uneven copy if the trimmer bar is marginal. Some of the symptoms you mention don't add up, but do what Adrian said. Don't fool with drum height. Finisher removal is in the manual, as is the dev housing. I don't know what the grinding was, especially since the machine runs without other symptoms.

Glenn