4200 blurry image

[dogsbody]

Hi All,
I now have to look after all the HP printers that are not under warranty at one of our universities, obviously have very little experience with this brand.
I have cleaned the transfer roller, the laser unit and generally inside the printer. They did not have another drum unit for me to try so before I start guessing I hope someone can help me out. The attached image is what I am trying to fix, there is a blur around all the text and blacks and greys seem to have a textured look. They reuse their paper so there is an image on the other side which you can see on the scan.
Any help is most appreciated.
Cheers,

[blackcat4866]

Most likely, the laser optics are dirty. To make sure that you have ruled out other factors load some plain white new paper, and a known good toner cartridge. =^..^=

Sorry just re-read your post. Did you clean inside the laser or just the slit glass? Moist paper could account for the whole thing.

[fixthecopier]

If they reuse the paper, they may use aftermarket cartridges to save money. If someone else has a 4200 on campus, take the cartridge out of the bad machine and carry it to another and see if it makes a bad print.

[dogsbody]

Thanks guys,
I only cleaned the slit glass of the laser, not inside so that is one to try. Will also try to find another of the same type for the drum unit. To make this easier are there other HP's that use the same drum unit. All the printers/mfp's are on the print server and named buy model and room number so it will make tracking one down easier.
Thanks again.

[dogsbody]

Hi again,
I was able to find another printer not too far away and tried the drum unit, it makes a great print, tried some of our paper as well.
I cleaned the inside of the laser for no result.
I am leaning towards the laser being at fault, which if i tell them they will just buy a new printer, but it would be nice to know what is at fault.
Cheers,

[dogsbody]

Hello again,
I now have 3 printers with this fault, 2 x 4200 and a 4350. The 4350 had a new fuser last month but that is all I have left. When I jam the machine before the fuser the print is great.
All three fusers look good however I nothing left that could cause the blur.
Anyone had any troubles with these fusers?
Cheers,

[wazza]

Looks like a problem with the fuser drive gears/assembly. Looks like the fuser is not rotating smoothly, like a vibration in it, possibly caused by the fuser drive gears being cracked or worn.

I have only limited experience of HP's myself, but it looks like fuser related. If you have checked the Upper Heat Roller is OK, remove the fuser and check the drive assembly for the fuser.

You said yourself that the image looked OK when stopped halfway through.

[danketch]

	Quote:			Originally Posted by dogsbody
	Hi All, I now have to look after all the HP printers that are not under warranty at one of our universities, obviously have very little experience with this brand. I have cleaned the transfer roller, the laser unit and generally inside the printer. They did not have another drum unit for me to try so before I start guessing I hope someone can help me out. The attached image is what I am trying to fix, there is a blur around all the text and blacks and greys seem to have a textured look. They reuse their paper so there is an image on the other side which you can see on the scan. Any help is most appreciated. Cheers,

may be you have an image in the back of the copy

[mattchall]

It is most likely the fuser. I've had quite a few 4000's, 4100's and 4200's where the fuser film causes blurry prints.

[blackcat4866]

danketch makes a valid point. Perhaps the toner from the previous images was made on a cooler fusing machine. When it passes through the hotter HP it loosens the old image and reprints it with the fuser.

We used to get this occasionally when a customer would print some fancy color letterhead on their color machine (fusing at 178C), then runs it through a second time to overlay the letter image on their B&W (which fuses at 190C).