Cleaning the transfer unit is a tricky and patient job.
- First you have to take it out, which already is a long process (as you figured it out by yourself).
- WARNING: touch the black belt as little as you can. It is very delicate and if you damage it will make smears on the paper.
- Unscrew some screws untill the black belt gets losen up.
- Carefully pull it down sideways from the rollers. Some of them are on springs so remember their position as they are going to fall apart.
- Clean the rubberized rollers of all the debris and dust, check if there is any debris inside the belt.
- Put the black belt back on and asemble the whole TU.
- Now you must clean the belt with a cloth untill it is super clean. Ideally wear cloth gloves because all the fingerprints stay on it. Use the wheels to rotate it.
- Put the TU back in the printer.
Well, it is an precise long job, but if you can save 700€ in a couple of hours then it is well worth it.
I just replaced the transfer unit in the current 7500 with a TU from another and it resolved the issue I was having. but I dont want to keep having to do that, too expensive and time consuming. I would like to know which part to clean to fix this so I can use the "bad" transfer units I pulled.
regardless I will avoid using the method of cleaning i am using to keep this from happening.
when I swapped out the transfer unit between two other 7500 printers, the replacement unit I put into the printer with this issue didnt have the problem, so it seems to be a problem the transfer unit developes after debris is shifted around inside the printer?
I seem to be having the same issue after attempting to clean out some excess toner; my wide prints have very similar shape of mark along the boarder of the paper. I was hoping you could help me identify which rollers/ contact points I will need to clean to fix this issue. Which panels/parts would I need to remove to get to these parts? I would greatly appreciate the help.
It was the transfer belt. But it is very easy to say "replace it" and very hard to do, because in EU it costs more than 700 Euro :)
I fixed it myself. The problem is, that there was some debris between the rollers and the belt foil. I had to disassemble it and clean the rollers.
Thank you for using the Support Forum. Please take a look at the solutions for smears or smudges. It seems like you may have tried some of these but make sure you also try different paper just to rule out a paper issue. If this does not help then please consider contacting your support centre for further assistance.
I own a Phaser 7500 and have troubles with repeating marks or smears on the lower side of the sheet - the one closer to the printer's screen. The marks are black and 8,2mm apart (see picture).
The troubleshooting page states that is a bad fuser but I checked it out and it's perfectly working. Also I took out the accumulator belt and found these identical toner marks on it - so this happens before the fuser anyway.
I checked the drums and they seem ok, I also cleaned everything.
The interesting part: I did the "Cleaning for repeating artifacts" on the printer menu. It prints 5 pages and the first one has strong marks, the second one a little less, the third one even less and the fifth one has no marks on it. But whenever I repeat this process the marks come back on the first page.
UPDATE: I did the "drums test" with 4 CMYK pages and they all print fine, but they all have the same black marks on the bottom. So it is not the bad drums.