Hp 2500 - colors come and go

[DCO57]

An HP 2500 here at my company has me stumped. One minute the yellow stops working, next printout the blue stops, next the yellow starts again...etc. The config page acts the same...one minute it doesn't show yellow...next it does, etc. Its mainly blue and yellow thats effected. The service manual is no help here. I cleaned and reseated all cartridges and ram, and reset the NVRAM. All toners are full and HP brand. No errors. I'm assuming its the DC controller... any thoughts please.
Doug - IBM

[redcow]

Start easy.

Print a menu map.
Cold Reset
Try printing. If no change...then swap out DC Controller

[prntrfxr]

Are these problems occuring from control panel or the computer. Use fresh paper. Make sure paper is in spec. Make sure color settings are set to Automatic. Check toner level of cartridges. Clean all sensors (80% of color laser problems is dirty sensors, especially in carousel machines). Perform calibrations. Last resort may be DC Controller, for this problem.

I've had blank pages before and fading on one side. Are you seeing anything like that? If you are its not DC Controller. Let us know results of above so we can help you further.

[DCO57]

Thank you both for the input.

I swapped the DC Controller for good measure....but no luck. Same issue.


I'll try color settings (the 2500 doesn't have a control panel so it'll have to be done via HP software on the server or a local PC).

Next...the point about the sensors is true.....I'll check my sensors. These carousel printers make allot of dust inside.

DCO57

[cs_steve]

Several suggestions:

1. I would still be suspicious of the toner cartridges ... even though they are HP & fairly full, they could still be defective. Can you swap in spares?
2. What about the imaging drum, fuser, transfer roller?

[Tomislav]

Remove top cover and formater board, on the right side of printer is mech. with motor that drives toner cartridges in circle.
On that mech. there is one solenoid that could be defective. Probably with time the solenoid starts to be sticky so when it is turned ON and OFF the lever of solenoind is still in ON position because of sticky solenoid.
A small piece of duck tape on solenoid should resolve your problem.

Hope this will help.

[prntrfxr]

When I said control panel, I meant print a test page from it to see if its software related instead of printer related. Tests you can print:

Demo page: After printer is at ready, press GO
Configuration page & supplies page: press GO and CANCEL JOB at the same time

To calibrate the printer: turn it off wait for 1 min and then turn it back on. Do this 3 times

To print an engine test: The engine test switch is inside tray 1, on the left side, just below the front cover.
Open tray 1, and then press the engine-test switch.

I agree with cs_steve's suggestions, but you need to eliminate things systematically, not just throw parts at the machine. It may be the solenoid and you can use the tape to see if it is, but dont make tape the fix. The solenoid is RH7-5339-000CN.

[DCO57]

Thanks for the tips guys...
but still nothing...actually it's now printing blank pages. It started doing all yellow for awhile...now nothing. The more I tested it, the worse it got.
Same with engine test...blank.
I've replaced the DC controller, formatter, checked solenoid(as suggested), cleaned sensors(ones I could get to), cleaned contacts (for toners and image drum), checked for slipping or cracked gears, checked both ribbon cables with meter, replaced toners and image drum.

I'm leaning towards:
1. laser (theres a controller board on it..maybe it gradually died..first not shooting yellow or blue pixels, then sporatically only shooting one pixel color or another until..now nothing)
2.Maybe I got a DOA DC controller - I've gotten dead parts before....a troubleshooters nightmare
3. Same with the formatter...maybe a dead part
4. Replacing both DIMMs, RAM and Flash.I'll try swapping them with a good unit.
5. LVPS. I'll check the voltages.

If anyone can think of a particular sensor or part that can slowly die (printing some colors for a few pages, then others, then gradually nothing).I'd greatly appreciate it.
Thanks for everyones help.
Doug

[MichaelTech]

Whoa!!! Ixnay on the duct tape! Plain old scotch tape is best.
Doubtfull it is the problem. The carousel may be just worn at the bushings, or may have silpped a notch. Check the alignment on the right side. Two small white nubs on the drive gear line up with a line INSIDE the carousel black indent. The left side lines up with a line on the edge.
H/V can be cutting out.

[DCO57]

Regarding the carousel...after closer inspection, I now know theres a problem with the toner cartridges not lining up with the imaging drum. I checked the alignment arrows on the gear / carousel and they point exactly, but somehow when the carousel is in the phase where each toner roller is pushed up against the imaging drum, only the yellow comes in contact...the other 3 are so out of alignment that the plastic cartridge pushes against the drum, not the roller (which also wipes any yellow off - yellow being the only toner powder actually being spread onto the drum.)
Since the alignment arrows are in sync, I guess its just worn bushings, as mentioned (thanks). Although its strange that the yellow lines up but the other 3 don't..
I'm trying to order not just the carousel, but maybe the rotary pressure assy, plate assy, rotary sensor, and anything related to gears and sensors that come in contact with the carousel (pg 244 service manual). I'd hate to have to take this all apart again.
Any other thoughts on what could be causing this mis-alignment of toner/image drum? I greatly appreciate all posts thus far...as well as any other thoughts on this situation. I'm new to this forum, but plan on participating allot.

BTW..
Regarding the hi and lo power supplies....forgot to mention, I swapped them also. (The stranger the problem is, the more chance its a voltage issue so for this case the power supplies were part of round one.)
Doug

[prntrfxr]

I didnt suggest this before because I didnt know if it was the same problem. Here are your steps:

Symptom:
Fading on one side
Blank pages

Problem:
One cause is defective toner cartridges, but more it is more frequently caused by misalignment of the cartridge carousel assembly. If a cartridge is installed incorrectly a misalignment can occur.

Resolution:
On every cartridge there should be arrows on the right and left sides and they should line up with the arrows on the print cover. If they don’t line up, the carousel is misaligned.

I. TONER CARTRIDGE NOT INSTALLED CORRECTLY - Remove the toner cartridge and reinstall correctly. If the problem is not corrected, perform the realignment procedure below.
II. DIRTY SCANNER LENS – Blow out toner/dust from scanner mirrors. It may be necessary to remove the scanner to clean with air. Do not touch mirror or lenses.
III. CAROUSEL OUT OF ALIGNMENT – Perform realignment procedure.
1.) Remove all covers
2.) Release carousel brake (use small screwdriver)
3.) Line up yellow carousel slot (Y on cartridge and Y on carousel)
4.) Notice that there are 2 black gears on the main drive shaft and 2 white gears that interlock with the carousel gears.
5.) There are 2 pins on the each of the white drive gears.
6.) Rotate the carousel and line up the pins with the marks on each of the black gears. The mark should be in the middle of the 2 pins on each of the gears. See example to the left.
IV. BLACK PLASTIC BUSHING – (RB2-9808)
V. CAROUSEL ASSEMBLY – (RG5-6910)
VI. CAROUSEL DRIVE ASSEMBLY - (RG5-6911)