Laserjet 4250

[MacDiesel12]

I need to know the name of the gear assembly that is on the left side if you are looking at the back of the printer and you pull the fuser out. It is the gear that drives the fuser. I thought it would be a part of the main drive, but it is not.

 

[hpwizzard]

That would be the swing plate assembly.
Also I "believe" there is a sort of servicenote on it (if you encounter grinding noises due to a worn out swing plate gear) covering costs expenses.
That means call your local HP support and they should launch a repair and dispatch a CE on-site with parts

 

[Michael52x]

Changing just the rear gear, and spacer, is not always enough. the middle gear in the swing plate assy. can get very worn, and continue to give you problems. It is a big job to remove components to be able to replace the entire assy.

"Impatience will reward you with dissatisfaction" RMS Cosmics'97

 

[hpwizzard]

Rear gear and space... Hmm. Must be part of the main gear assy ?
The swingplate gear exchange is actually quite easy and takes approx 10 minutes...
First remove the back lid, fuser and any duplexer if you have such.
Next remove the formatter cage (leave the formatter inside)
Behind where the formatter cage was seated you will be able to locate the single screw that holds the middle gear in the swing plate assy. Remove the screw and you can take out the gear itself. There is absolutely no need to remove the whole assy including the plate as the only thing damaged will be the gear.
Now with the gear removed, install the new one from the assy and use a thin screwdriver from the side to get the gear in place before inserting the screw.
With the gear now exchanged you can reinstall the formatter cage and the reamining parts and you're done.

 

[Michael52x]

Well yes, just the one gear is an easy job, but not always
cures the problem. the entire assy. is a pain to do, and since we track the repairs of each unit, after the one gear is changed a couple of times, it will need the entire assy.

"Impatience will reward you with dissatisfaction" RMS Cosmics'97

 

[hpwizzard]

Interesting... I have seldom heard of any cases where the swing plate gear was replaced more than once in the entire life of any of these printers (LJ 4250/4350 series)
In those few cases it was the fuser gears that where damaged causing the swing plate gear to granulate again.
I don't understand if you say that you had cases where you had to replace the swing plate gear several times before ending up having to replace the main drive assy ?
To my knowledge the swing plate gear(s) is driven by the fuser and not the main gear. The main gear drives the fuser and the fuser then rotates one of the gears in the swing plate. The other gear in the swing plate drives the feed from tray 2.
I know that the main drive might get worn or damaged by other causes mostly due to excess printing after < 1.000.000 pages but besides that never really seen any cases where the swing plate gears where involved.
Sorry for digging further into this but I am just curious (by nature!) to hear and maybe learn if there are issues with this printer series that I have missed

 

[pbing]

HI

Try this link this show how to reomve the most lighly part giving you this noise

Thanks
PB

http://www.partsnow.com/service_today/ST0207.pdf

 

[Michael52x]

hpwiz, I did not mean the main gear assy. just the swingplate assy. I changed just the rear gear and spacer, and still had a problem. The inner gear was worn even worse.

"Impatience will reward you with dissatisfaction" RMS Cosmics'97

 

[ClintonM]

Hi folks,
I just went through the ugly task of replacing the entire swing plate assembly on one of my 4250's. The issue I get now is that once it gets back together and tries to print it jams continuously. I've traced it back to the fact that the fuser gears are not engaging and spinning the paper through the fuser, even though I have tested this fuser on another 4250 without a problem. Is there a tip that anyone could provide to me to watch for? Please note that I have been troubleshooting with the side hood off and I can confirm that the small motor that turns the swing plate gears is working, but it almost seems like the gears don't touch to spin together. Getting frustrated here...

Clint M - Fredericton, NB Canada

 

[gbaughma]

Clint:

That should be a new thread.



Just my 2¢
-Cole's Law: Shredded cabbage

--Greg

http://parallel.tzo.com

 

[Michael52x]

If unit goes to ready, and then you get jams, it could be several other things. Does it jam up immediately at start?
The swing plate has a tang that is operated by a cam. You may not have got it set in right. Otherwise, it may be a fault fuser clip, or the Power supply is just a hair too low.Loosen the scres on both sides, and, with the fuser in, lift up and tighten.

"Impatience will reward you with dissatisfaction" RMS Cosmics'97

 

[ClintonM]

Thanks for the advice Michael52x. It turns out the swing plate that I was sold was actually for a LJ 4200 and it must be a fraction too small for the gear to actuate the fuser assembly on the 4250. So after all is said and done I ended up tearing it all down again and just using the gray coloured gear from the new part and installed the old swing plate with it. Works like a charm now, but I think I will be seeing 4250's in my sleep for a month! Anyhow, the guy who sold me the part is a little red-faced and will be buying the first round the next time he sees me at the pub .

Clint M