HP 5Si - vertical streeks on top of page

[DavePL]

When we print from our 5Si we get light gray vertical streeks on the top of every page, (just the top 1/4 of the page). They're evenly spaced, about 2" apart with a large streek and a small one alternating. The pattern shifts from right to left on successive pages and repeats every other page. They look like prints made by wheels in the paper path.
We replaced the toner cartridge and the fuser with new ones. We cleaned all the wheels and rollers we could see, including 6 white rollers above the fuser that were coated with a hard black coating.
This had no effect. We were wondering if there may be some rollers or wheels that are hidden that can be cleaned, and how we could disassemble the printer to find them, (the owner's manual doesn't give too much detail on that).

 

[rahowa]

I am going to suppose that you are using letter 8.5x11" paper. If you have changed the toner and fuser the next step is to clean/replace the transfer roller. Its the long black sponge roller under where the toner drum contacts the paper. Try pulling it out and cleaning it. Don't touch it with your fingers...hold it with a piece of paper or rubber gloves. Otherwise there are rollers before there. If you remove the toner and lift the 'gate' (green handled) you will see deeper into the paper path. The rollers on this gate are the registration rollers. It is possible that they need to be cleaned. It is pretty easy to remove. 4 screws, one harness, and the cover over the gears. Any questions about it feel free to ask. Put not your trust in princes.

 

[Melapa]

This sounds like it is the bushing that holds the transfer roller in place if you have replaced the toner and the fuser.
If you open the top cover of the printer and remove the toner cartridge you will see the black spongy roller underneath. Push down on either side of this roller, and it should spring back into position, if it does not spring back into position on both sides then the bushings are not holding the transfer roller in the correct position. At each side of the transfer roller "housing" you should see clips with springs on (only visible when the transfer roller is removed), make sure that these are holding the transfer roller in the correct position.

You can also try a half test on the printer. Try printing a page to the printer, and stop it once about 2/3 of the page has been taken into the printer, then check the drum on the toner cartridge to see if the defect is on this. if the defect is opn this you will know that the toner cartride or something before it is causing the problem.

Also make sure that the problem is happening on all media and from all trays to try and narrow down what is causing the issue My advice is limited to my personal opinion, and the information I have been provided with. Paul Melarkey

http://www.stream.com

 

[DavePL]

I appreciate the feedback, and it does look like the problem may be the spongy registration roller, or something near that. The springs seem OK that hold the roller in place. I tried cleaning it with wet paper towels and removed a lot of black toner. However the problem is still the same. I tried removing the assembly that holds the roller, and found two screws under a metal plate on a hinge, but those don't seem to loosen it. We found the plastic cover over some gears, it fits loosely but doesn't seem to remove easilly. We're wondering what order to follow to remove the assembly, in order to clean it.
Meanwhile we are also going to try some laser printer cleaning sheets, and see if that improves the print quality.

 

[k1c2]

You say the streaks are "about" 2 inches apart. That's close to OPC and dev roller sizes in the cartridge. Seeing as how you've replaced the toner, the next closest roller would be the registration roller (1.73 inches). Remove the assembly and give all a good cleaning/conditioning.

 

[Melapa]

Hi Dave,

For the 5si there is a part called a maintenance kit, which contains the transfer roller, by cleaning it with wet towels, you have probably contaminated it now and it will need replaced. The part that this roller sits on is called the feed assembly, and the whole unit would need to be replaced if damaged My advice is limited to my personal opinion, and the information I have been provided with. Paul Melarkey

http://www.stream.com

 

[DavePL]

We found directions for removing and replacing the sponge roller (called the transfer roller) on HP's website.
The assembly fits into place, no tools are needed to remove and reinstall it. I cleaned it again with a dry cloth and It looks clean by sight, but the pages are still streeked. So our next step will be to get a new transfer roller.

 

[rahowa]

Yeah, my 5si service manual shows a couple of items that can cause this problem at about 2" apart. Is it possible for you to try a known working toner from another machine? Toner and transfer roller should be the main causes. Put not your trust in princes.

 

[DavePL]

The problem turned out to be caused by bad toner cartridges. They were remanufactured, brand new out of the box, and both were bad, that suggests a whole batch of them was bad, specifically, the drums were bad. Putting in a different brand of toner cartridge fixed the problem. Then during the day the copies started to get streeked again, in a similar way as before, and then later on, the problem totally cleared up by itself. To be safe, we installed a new transfer roller. We guessed it might have been causing intermitant problems.