robotmac

asked Apr 20, 2005 at 3:26pm
Hp HP LaserJet 4M

HP LaserJet 4M - Wavy paper edges printouts

I am having a problem with HP LaserJet 4M. Wavy (or bent) edges on the printouts; I have two LJ4M which both suffer from this problem. I have tried papers from a few different manufactures, but no luck.

This is physically in the paper, it has nothing to do with the print. Wavy paper margins in lengthwise direction. From the vertical edges of the paper, half an inch in towards the center of the paper.

With bent I mean; this appear in and around the middle of the paper, in 2-3 inch increments (lengthwise) or so. It looks as if the edges is bent one way and the next increment is bent in the opposite direction, thereby creating a wavy look.

Any help would be most appreciated, thanks
mike
Can you post a sample of the problem. Are you using new toners or recharged ones?
by dmzcompute on Apr 20, 2005 at 4:33pm Add comment
Thank you for replying!

Sorry, no digital camera. I am using HP original toner.

The 'waves' is not in the print, it is in the paper. The vertical edges of the paper is curly/wavy. Like it has been grabbed to hard, or perhaps warmed up to long.

As I mentioned; I have two LJ4M and one of them have a bigger issue with this than the other. I have swapped the fuser assembly between them. With no luck. The ’bad’ one still produced prinouts with a more pronounced curl than the other.

I have also swapped toner cartridges between them. Also with no change.

This have led me to exclude fuser assembly and cartridges.

Thanks again,
mike
by robotmac on Apr 20, 2005 at 4:52pm Add comment
I've never seen a vertical wave in the paper. The only thing that could cause it would be the fuser, but you've already tried that as well as different paper. Are the shipping levers in the down position? That could cause uneven heating. The levers are on the inside part of the vertical metal fuser supports.
by moe on Apr 20, 2005 at 4:55pm Add comment
The more I think about it, the more I think these are probably horizontal accordion folds as is common on these models. I just can't see them doing vertical ones. I've seen thousands of these printers and can't believe 2 of them are doing it. Try this experiment for me. When the paper starts to exit the top, immediately grab it and exert a steady pull on it till it comes out all the way. Is the problem still there?
Another thought just occured to me. This wouldn't be a 4MV by any chance. That feeds paper in the landscape access and then the paper could have vertical folding. If so, then follow the same instructions I gave you above for pulling on the paper.
by moe on Apr 20, 2005 at 5:03pm Add comment
Thank you for replying!

Vertical; well, how can I say it different … When the paper comes out of the printer, two of its margins are wavy/curly. Since the direction of the print is: ’portrait’, it is the vertical margins. Not the shorter horizontal margins.

When I say it is not in the print. I mean that it is not the the text that is wavy. The printer output great text quality.

Thanks again,
mike
by robotmac on Apr 20, 2005 at 5:09pm Add comment
Is this in reality a 4MV not a 4M?
by moe on Apr 20, 2005 at 5:13pm Add comment
Well, let me prove that it is not just these two. Here is a link to a newsgroup discussion way back in 1994:

http://groups.google.se

mike
by robotmac on Apr 20, 2005 at 5:13pm Add comment
Both of them are guaranteed LJ4M.
by robotmac on Apr 20, 2005 at 5:17pm Add comment
The waves/curls are not at all accordion-like. The accordion error is easily fixed with a maintanence kit.
by robotmac on Apr 20, 2005 at 5:22pm Add comment
Lets get back to basics. Do a half test. Put a sheet of paper on the manual feeder and send a sheet with 1 character from the computer. When the sheet is about 2/3 of the way in lift up the toner door and remove the toner. Remove the sheet and see if the defect is in the paper. If not your issue is the fuser and since you say both printers do it, but one is more pronounced, I would lean towards the fuser as being the issue. If the defect is there then it has to be something to do with your paper since there is nothing in the initial print stage which could cause this.
by dmzcompute on Apr 20, 2005 at 5:23pm Add comment
I have stopped the paper at various stages during printing. I have also stopped it in the middle of the fuser, but the curls are there. This is why I think it is something mechanical. It happens before the papper hit the fuser.

This error appear wether I print from: multipurpose tray, paper cassette or lower cassette.
by robotmac on Apr 20, 2005 at 5:29pm Add comment
I have tried paper from different manufactures. Right now I have brand x in one of them, and a Xerox laser printer paper in the other.
by robotmac on Apr 20, 2005 at 5:32pm Add comment
My next, and last, move is to swap the main transport mechanism between the two.

Thank you for helping, very kind of you,
mike
by robotmac on Apr 20, 2005 at 5:35pm Add comment
Here is a link to a posting in one of the forums where a lady mention that she fixed a wavy edges issue:

http://www.fixyourownprinter.com/forums/laser/855#1

Unfortunately the sales dept. could not tell me which repair kit she was refers to.
by robotmac on Apr 20, 2005 at 5:47pm Add comment
There is nothing in the manual feed path besides the fuser which could cause what you describe. I would now check on conditions in the room where the printer is located. Prehaps to much humidity or something. This assumes that the wavey issue is not toner but rather a curling of the paper. If it is a toner issue you may wnat to check on the transfer roller. Keep in mind what one person describes as wavey may be curling to another. Can you possibly scan the image and post.
by dmzcompute on Apr 20, 2005 at 6:55pm Add comment
Thank you,

So your verdict is the fuser assembly. Which part, the fuser roller?
by robotmac on Apr 21, 2005 at 2:59pm Add comment
Based on what you reported my verdict is not the fuser. You said that you stopped the paper before the fuser and it had waves. If that is the case it would not be the fuser. Again media or enviornment. As I posted it could also be something with the printing cycle if the curls you see are actually image defects like a grey band or something which makes the paper look like curling but rather something adhered to the paper. Best I can do for you without seeing a sample.
by dmzcompute on Apr 21, 2005 at 3:12pm Add comment
Sorry, I misunderstood what you said. English is not my native language.

I have done a, simple, sketch portraying the look: http://www.monoform.com/temporar/wavy_edges.html

No grey band, or anything adhered.

I will buy (yet) another brand of paper so I get fresh paper which have not been in the environment.

I will be back, thanks :)
by robotmac on Apr 21, 2005 at 4:22pm Add comment
Logically, this can't happen. If the paper was bent like in the illustration prior to going through the fuser, the fuser would not only flatten it, but cause vertical creases in the paper. The paper could not possibly get vertical waves in it before going through the fuser. There's nothing in the printer that could cause that. The paper comes out of the registration guide flat and goes between the cartridge and transfer roller. How could vertical waves be put in between those two points? Likewise it couldn't possibly happen between registration and the fuser. Something like that would have to have a cause and there just isn't anything that could cause it. Since the fuser uses heat and pressure, similar to an iron on cloth, it will totally flatten paper going through it. It is totally impossible for it to cause vertical waves. It can cause horizontal ones because the roller that's above it isn't turning fast enough to move the paper that's coming out of the fuser. This one I'd have to see to believe. If this were a 4MV, it would make logical sense, but not in a 4M.
by moe on Apr 21, 2005 at 4:47pm Add comment
Moe have to agree with you 100\%. Is it possible we are talking about horizontal and not vertical waves and the user is giving us incorrect information. Tell you what robotmac, why don't you do the drawing again or add to this drawing which side of the paper are those waves. Either the 8 1/2 inch or 11 inch side. Mark it so we can make sure there is no misunderstanding here.
by dmzcompute on Apr 21, 2005 at 5:15pm Add comment