unknown

asked Mar 9, 2005 at 12:35pm
Hp HP Color LaserJet 4550

HP Color LaserJet 4550 Streaking

I'm having a streaking problem with an HP 4550 Color LaserJet printer.

The streaks are vertical, and go across the whole page (across all colors on the color density calibration page. They are in the same place every single time, and look exactly the same (color-wise) so if I print the same thing 10 times, the prints (including the streaks) will look identical.

They span the whole page side to side, eventhough most are in the middle third of the page.

I cleaned everything I could get to out really good, shook up all the toner cartridges, and even replaced the fuser (which had some noticible gashes in the rollers). None of that made any difference, the prints still come out exactly the same.

Anyone have any suggestions as to what this can be caused by?

Thanks in advance,
--Dmitriy
Sounds like a bad OPC (drum) - located in the top draw. What is the printer showing as the life remaining on the consumables?
by huckle on Mar 9, 2005 at 1:11pm Add comment
All the consumables have more than 50\% of life left, the fuser, which I replaced, was the lowest one at 53\%, all the other ones are over 60.

Are you talking about the HP imaging drum or something like that? I replaced that only a few months ago, and I think it has over 80\% life left.

Anything else it could be?

Thanks!
--Dmitriy
by unknown on Mar 9, 2005 at 1:19pm Add comment
possibly dirty window on the laser/scanner assy. Has the printer been moved recently?
What colour are the streaks?

by huckle on Mar 9, 2005 at 1:26pm Add comment
Hmm... Where is this laser/scanner assembly? What does it look like? The printer was only turned around for me to look at it, which was already after the streaks began.

The streaks are of the same color as whatever is supposed to be there... kind of like a discoloration... or the color is just less intense in the streak than in the normal area around it.

Thanks!
--Dmitriy
by unknown on Mar 9, 2005 at 1:30pm Add comment
Definitely sounds like the laser/scanner then. I've had this myself - The toner in these printers gets EVERYWHERE - much more so than on other printers. You need to remove the top cover (side covers first). The scanner is the black unit towards the front. don't use compressed air to clean!! You can use a lint free cloth wrapped around a cotton bud to clean.
by huckle on Mar 9, 2005 at 1:37pm Add comment
Thinking about it, you might be able to clean the window without removing any colours, via the top draw using the blue brush - i really can't remember - sorry. The scanner window will be facing the drum.
by huckle on Mar 9, 2005 at 1:39pm Add comment
Will try that! Thanks!
by unknown on Mar 9, 2005 at 1:44pm Add comment
This did not help, the print outs still look exactly the same.

To clarify, the window is right under the imaging drum, which is in the top drawer, and it is cleaned with the little brush that is in the middle drawer (where the belt is).

At this point I'm stuck, I don't know whether I should start replacing everything, or just get another printer.

Anyone have any other ideas?

Thanks,
--Dmitriy
by unknown on Mar 16, 2005 at 9:56am Add comment
I think you may have cleaned the density sensor rather than the scanner window.
by huckle on Mar 16, 2005 at 10:08am Add comment
Watch your email. I am sending you something which should help.
by dmzcompute on Mar 16, 2005 at 10:17am Add comment
I've followed the instructions you sent me to clean the scanner window, and while at it, cleaned everything else I had access to.

The problem however, persists, the printouts are still streaked exactly the same.

Any ideas?

Thanks,
--Dmitriy
by unknown on Mar 23, 2005 at 10:05am Add comment
I'm currently doing some maintenance on this machine. The transfer belt is usually the main cause of this print defect. Try giving it a good clean with a toner vac or toner wipes. It's in the middle drawer. Good luck.
by dantheman2008 on Jan 7, 2008 at 5:10am Add comment
Oh I also forgot to mention to clean out behind and under the fuser. It gathers there. The transfer belt does come out so you can give it a good cleaning also the same with the drum in top drawer. Aslo clean out the toner carriage. Rotate to each toner and use small amounts of canned air and toner wipes to clean it out. then work your way down the printer. I really do hate how nasty these printers get inside. Not the greatest design.
by dantheman2008 on Jan 7, 2008 at 7:10am Add comment
We actually got rid of this printer a while ago in favor of a newer HP Color Laser jet (they are only $700-$800 now!). The old one was just a pain to use and maintain... the new one is faster, better print quality...etc.
by Anonymous on Jan 7, 2008 at 8:15am Add comment
I do agree that the Color LJ 4550 is a pain to maintain. It has been a constant headache. Beware of some of the newer cheaper Color Lasers. the 2605 has been a nightmare for me. also the 2805MFP as well. Same system as the 2550 and still a mess.
by dantheman2008 on Jan 7, 2008 at 9:18am Add comment
If you have vertical streaks, that fade the colour of whatever is beneath them, then it could be the laser/scanner at the top. If the streaking is not on all of the colours, sometimes goes away or appears in different places then IT is probably NOT the laser/scanner assembly.

the laser assembly is hard to get to - I have just done it and it was a bit scary.

Make sure the printer is off, disconnected and has had 30 mins or so to cool down.

First you have to get the whole plastic top off the printer. the top has two screws at the back, and clips round the front. I had to remove the drum kit (don't expose to sunlight) and one of the sides too before i worked it out.

Now you will see a large metal surface with about 10 screws in it - get them all out and put the metal cover to one side.

Inside you will see a plate with a yellow warning sticker on it. This is the one you need to get off. it has about 6 black screws. remove the screws, and remove the black wire holder on the right. some of the wires are connected to the laser unit, through the top of the plate with the yellow sticker on it. carefully ease this connection out.

BE CAREFUL - do not get dust inside the laser housing.

using dry q-tips brush all the optical surfaces. It may not be obvious which one has dust on it. now put it all back together again.

hold your breath and see if it worked!

dave
by unknown on Mar 13, 2008 at 3:22am Add comment
Seems that Dmitriy had the same problem I have: vertical gray streaking with poor color (also in vertical lines through all colors). The streaking occurs most in the middle of the page although it is evident from margin to margin. It is not clear which if any of the interventions solved the problem. So what worked and what should I do?

I have cleaned the density sensor, the laser/scanner assembly, all the belts and roller I could get to. The dust tray is empty--it was when I took it out to check it. Actually, despite the evidence if toner dust, I was surprised how clean it is inside.

The fuser has 85\% life remaining;
the transfer has 79\% life remaining;
the drum has 42\% life remaining.

We replaced the black toner cartridge just before the problems started occuring. It sat in our office for about 3 months in its packaging before we put it in the printer.

I'll appreciate any help you can give. This forum helped me correct several problems with my HP Laserjet IIIp.
by Bill Foster on Jan 20, 2010 at 7:58am Add comment
Streaking in color or gray is a sign of a failing drum unit. I do not care what percentage the drum is at. You have to remove it, flip back the shutter over the drum and look at the drum. If you see any toner on the drum you need to replace it plain and simple. No sort of cleaning or adjustment will fix the issue. The drum wiper blade has gone south and the drum unit needs to be replaced.
by dmzcompute on Jan 20, 2010 at 4:47pm Add comment
I just ordered a new drum kit. Thanks for the advice. I'll let you know how it works.
by Bill Foster on Jan 21, 2010 at 8:42am Add comment
Just thought I'd add our own experience on this - we had print quality problems which consisted of vertical streaks, several spots (less than one millimeter in diameter), and the inconsistent colours (patchy).

The vertical streaks were fixed by replaced the drum, whilst the spots disappeared after replacing the transfer kit. The patchiness was resolved by replacing the toners and giving the sensors a good wipe.

It seems that every now and again toner dust gets into places where it shouldn't... requiring the replacement of consumables and sensor cleaning. The only component which seems unaffected by this is the fuser!
by pl720 on Feb 1, 2010 at 4:14pm Add comment
Thanks for your input. I replaced the drum two days ago, and it took care of all the problems. The printer is printing like new again. I'm really appreciative of the assistance I have received via this website. I now have two laserjet printers working like new and never had to call in a technician.
by Bill Foster on Feb 1, 2010 at 8:41pm Add comment
I have a problem with the right side of the paper, when printing the demo, is very light with a yellow tone. I have done everything: cleaned behind the transfer kit, cleaned under the fuser, emptied the waste tray, checked the drum and transfer kit by changing them with my other 4550, and they worked fine in the other printer. I even opened the top, clear down to the optical lens and tried to clean them. It looked very clean in there with no toner. I have cleaned out toner by taking out cartridges and cleaning down in there, and cleaned everything I can think of. Still, the right 1/4 of the page is very light, with streaks, and kind of yellow. Any ideas????
by Linda K on Jan 2, 2012 at 3:50pm Add comment
plz my hp color laser jet 4550 is printing only black and white what can i do to solve it plz respond
by lord razor on Jun 23, 2015 at 6:50am Add comment
plz my hp color laser jet 4550 printing only black and white what can i do
by lord razor on Jun 23, 2015 at 7:04am Add comment
Does it print color on the demo page from the printer control panel?
If yes, then the computer is set to print black and white.
by moe on Jun 23, 2015 at 11:07am Add comment