asked Apr 19, 2007 at 10:57am
Hp HP Color LaserJet 2840

HP 2840 printing problem

My client had replaced the imaging drum unit a week ago. Yesterday had replaced the 3 color cartridges and now when he prints, the left side of the page is blank. I called a fellow tech about this problem. He said the carousel is out of alignment. How do i re align the carousel? Or is the problem somewhere else?
Definately a carousel alignment issue. Its a big job so i'd advise getting a service manual before attempting this. It gives the step by step procedure!
by Anonymous on Apr 19, 2007 at 12:59pm Add comment
what causes the carousel to go out of alignment? - donovan619
Any advice on DIY carousel alignment proceedure??? HP 2840.
by Tim DeGross on Jan 9, 2008 at 6:12pm Add comment
Can someone email a service manual for Hp 2840 please? I have the same problem with the half print! Thx [email protected]
by mojomonty on Feb 27, 2008 at 4:25pm Add comment
does anyone have a manual?
by jerry9552 on Mar 4, 2008 at 12:09pm Add comment
Refer to page 203 at the link below. Will be up for only 7 days and do not ask me to post again.
by dmzcompute on Mar 4, 2008 at 2:32pm Add comment
I actually found this post and knew I had to do it. I used the link given (much better than the manual itself) and this was no easy task at all (make sure you have plenty of room for putting pieces aside) and remember where you unplug cables from.
After hours I got into it and i did find it out of alignment. corrected and got everything back together. Now it comes up like it is supposed to but when i try to print the configuration page i get an "engine error" I cant figure that out if you have any ideas DZM I would surley appreciate it. I do thank you for the link though, I had the service manual but your link made it much easier.

[email protected] - jamesmoore
dmzcompute posted how to aligin 2840. just saw it today and does anyone have a copy.
it is not there anymore
ed - edrussin
The poster above should be banned from this site. Do not refer people to a site to make money. Here is it one more time and I mean the last time. Refer to the last page which is 203 and the rest are the instructions. 7 days only.
by dmzcompute on Jul 1, 2008 at 4:31pm Add comment
I have the same issue as above-Not printing on the left side of pages.I went threw the disassemble procedures and discovered that the gear is right on the money. ???? What else could cause this issue-Bad carousel ? any ideas moe or any one else experience this.
by unknown on Aug 6, 2008 at 7:48am Add comment
Correction-Manual had me check left side gear but the right side was misalighned after re-alighning worked great.
by unknown on Aug 12, 2008 at 12:41pm Add comment
by unknown on Nov 21, 2008 at 10:16pm Add comment
I put in an aftermarket Magenta toner cartridge and it made a bunch of noice and did not work, the printer was telling me to replace the cartridge, even though it said it was 100\%.. After that everything on the left side did not show up, only about an inch on the right side of the page was printing. I did online tech support and they said it needed the carousel aligned, after I tried the genuine parts in it, it was still messed up. Seems like the gears in the cartride would not move and were locked up, as I can move the rollers on the HP toner that I took out that was empty and could not move the new aftermarkt rollers. (by hand)
by Anonymous on Mar 2, 2009 at 10:20am Add comment
I have a similar problem too with a 2840. I've already aligned the caroussel but it didn't help. Manual says: "replace caroussel". Do you think it will help? The caroussel looks in good condition.

Thanks for any help.
by dodika on Apr 29, 2009 at 8:06am Add comment
Replace the carousel didn't help. I spent two days to find the real problem. Again those refilled toners. Two from the four toner was too tight. When i tried to turn the gear on them by hand it was very hard on the other two it went easy.

So i very very much recommend to everybody who has the half page problem, to check the toners first. - dodika
I have a similar problem too with hp 2840 they said it needed the
carousel aligned . how to aligned carousel ?
by unknown on May 9, 2009 at 11:50pm Add comment
Yep, you are right! If the toner is hard to turn then it kicks the carriage out of sink. My black was almost not possible to turn by hand. New toner fixed it, and yes it was an aftermarket toner. I did buy the manuel and reset the carriage, all the time wondering why it was out of time in the first place. Now we know....!!! Thank you!
by Anonymous on Feb 1, 2010 at 6:47pm Add comment
I had the same fading problem. The printer was printing only the vertical half of the page. I downloaded the service manual and tried to re-index the carousel. We ended up indexing one side but left the other one (dumb move cause the problem still persisted). It took about a month for me to get the courage and time (takes about 1 hr in total) to try again. This time we indexed both right and left carousels and the printer prints beautifully!

Google and download the HP service manual and a 2-pg PDF on how to re-index the carousel. Thanks whomever put those resources up. BTW--I want to plug a new printer I bought. Because of this indexing problem and not having enough time to fix it, I went out and bought a Brother MFC 9840 CDW and it's an sweet little printer. It's quieter and prints duplex! If you're looking to upgrade, go with a Brother.
by unknown on Mar 10, 2011 at 4:55pm Add comment
You DON'T have to take it apart to index it. The only reason you'd have to take it apart is to repair the solenoid, which can cause similar problems. If you see the indexing is off, all you need to do is stick a straightened paper clip in on the right side, near the top, to unlock the carousel. Take out the toner cartridges and then turn it to the yellow and look for the index mark on the left side, pull out on the gear on the right and drop it into index on that side. Takes less than 10 minutes.
by moe on Mar 10, 2011 at 7:07pm Add comment
I have been plagued with the same problem on my 2820 for the past few days. This is my issue now:

I once successfully, by chance, got a paperclip to unlock the carousel solenoid lock, but couldn't do it after that. (Had to try to realign the carousel, as first time it slipped or something.) Anyway, in poking around, the little, white plastic piece in front of the solenoid got detached and is now floating around right inside there. I can see it, but can't reattach it.

Any help???

Thanks so much,
So frustrated,
Plus, also just bought 3 new cartridges!! ARGH...

by catziki on Apr 3, 2011 at 10:30am Add comment
I seriously don't understand how you managed to dislodge that with just a paper clip. The bad news is that you'll have to take the whole top assembly off in order to reinstall it. They you have to hope that you didn't break the clip that attaches it. It slips down onto a metal post and latches at the bottom. The good news is that it serves no useful function except as to act as a guide for the paper clip to release the brake solenoid. The bad news is that you still have to take the top off to release the solenoid so you can index it. You'll probably need a service manual to take it apart. There's a link above. Try not to break it any worse.
by moe on Apr 3, 2011 at 11:41am Add comment
check this it helped me a lot
by Truckie on Apr 5, 2011 at 8:38am Add comment
Video does not show how to release the carousel to remove the cartridges. It also does not show the index marks on both sides of the carousel. You should align to the index marks to make sure the alignment is correct so you don't have to repeat it. While his explanation of the cause my be half right, all the cartridges that I've ever seen cause the problem were seized and couldn't turn. That's what caused the carousel gear to jump out of alignment. - moe
My problems with this printer started when I started using third party companies cartridges instead of HP only. It started making a loud noise then all of a sudden, the printer started asking me to install cartridges when all colors where in already. I did a little search and found out the problem was that those cheap cartridges caused the carousel to be misaligned. I looked at a few videos and read some reports and apparently "fixed" the problem because the first time I turned the printer on after aligning the carousel no message appeared and it seemed it was reading all of them. Then I tried making a copy and it came out blank. It seems like one side of the carousel is crooked and even though I align it when I try to print or make a copy it gets crooked again. Does anyone know what I can do to fix it? Should I just call a tech?
by correa_ms on Apr 5, 2011 at 2:55pm Add comment
If you're putting those cartridges back in, then you'll continue having the problem. Simply turn the gear on each cartridge and the ones that won't turn shouldn't go back in. You're also taking chances with the other ones, but hopefully they won't seize up as well. - moe
I know that my problem was the carousel misalignment. My next
problem was trying to figure out what everyone else seemed to think was so simple: Sticking the paperclip in to disengage the carousel lock. That's what got me screwed up. I couldn't tell what exactly to do/where with the paperclip.

So I fiddled around and now the little white plastic thingie is floating around inside that window facing the solenoid....

Still can't fix it...

Is there an easy way to expose that area??

Anyone? Anyone? Bueller?

by catziki on Apr 5, 2011 at 6:30pm Add comment
I guess it's my fault. I didn't realize that I had to elaborate on straightening out a paper clip, sliding it down into the hole until the carousel released. I never imagined someone would try to pry the plastic guide off with the paper clip. I'm still amazed that even happened. Short story is, you destroyed the easy way. Only thing left is the hard way, which involves removing the entire top assembly and hopefully being able to reinstall that guide or there is even more disassembly required.
I'm thinking I should probably do an instructional video. - moe
Well, let me say that I have no problem straightening paper clips! And I didn't TRY to pry the white
plastic thing off, I just did not know what the paper clip was supposed to touch, lift up, etc...
After trying many pokes, which did nothing, I thought, "Maybe this white thing is the part that is supposed to be lifted up!"

I need to know how to remove the top assembly. Can anyone help me do this?

by catziki on Apr 6, 2011 at 8:07am Add comment
Here's the service manual
by moe on Apr 6, 2011 at 9:34am Add comment
Well I created a short video on youtube that shows exactly how to unlock the carousel & I'm quite proud of it since it took me a year to figure out how the clutch lock works. I don't use a paper clip any more but the straw from my can of air.

Go to either: & to the HP repair videos section & to the HP 2840 video or straight to this link

As Moe stated, generally only the locked up toner gear causes the carousel gear teeth to mis-align.
The 3rd party toners that lock up do so because the rubber cleaning blade popps backwards from improperly placed or no dry lubricant on the blade & jams up the developer roller.
by unknown on May 3, 2011 at 10:25pm Add comment
I bought generic ink and put in the wrong size cartridge on my hp2840. Now the carousel's jammed. I think I could disassemble it and get out the wrong ink cartridge if I knew how. The user manual's no help. Anyone have a service manual I could look at? I'd sure appreciate it. siena (206) 697-6585
by sienaross on Jun 2, 2011 at 1:06pm Add comment
Look at the post directly above yours. - moe
Thank you, hp-printer-dave! Very much appreciated. You video was the only thing that helped me find out how to release it. You're the best, mate.
by unknown on Jun 14, 2011 at 3:26pm Add comment
Thanks too to Dave for the video. I couldn't find where to stick the paper clip and besides after watching, my WD40 red tube worked better anyway.

I fixed the registration and it immediately jumped out again. Then I found I had one stiff (almost jammed) toner cartridge mechanism. Replaced that and all is well again.

Now I just need a new tray2 pickup roller and my clunky old 2840 will be going again.

Have noted the recommendations on a Brother MFC 9840 CDW.
by unknown on Jul 14, 2011 at 8:36pm Add comment
I made a short video as well, building on what users moe and hp-printer-dave have already posted.

by unknown on Sep 13, 2011 at 8:30pm Add comment
i have self problem please salution for the"engine error"
by sunur on Feb 9, 2014 at 9:39am Add comment