hp color laserjet 2840 missing yellow

[hunkeydorey]

Several weeks ago the color YELLOW stopped printing although all other colors worked fine. Supplies status showed over 60% yellow still remained along with the other colors. Thinking that the 3rd party YELLOW cartridge was the culprit I ordered and replaced the Yellow with a new HP Cartridge 122A Q3962A. Small improvement by very light yellow showing up on Supplies Status Report but yellow bar on bottom missing. The firmware was updated this evening, drivers reloaded and tested with Post Script and PCL6,  pulled all cartridges and tried re allignment, cold boot and changed power source to wall output versus surge protected, all to no avail. Any suggested next steps?

[SHThompson]

This one I'll have to think over, the usual failure on this machine makes it only print yellow.

The only thing I can think of that is unique to that color is the slot in the carousel that it fits into. If you remove the toner and inspect the swap was it have any appearance of damage? Compare it to another slot.

If the carousel needs to be replaced it is a rather difficult a job.

[hunkeydorey]

Thanks for the quick response.

I examined the carousel carefully and could not find any discrepancies or differences between the other cartridge slots. Also today tried putting the yellow color saturation to max on 2ndary Service menu with no noticeable effect.

I forgot to mention before that when I did firmware download and upgrade followed by a print of the config, YELLOW WORKED but then it DROPPED MAGENTA until I powered off the system and the MISSING YELLOW reappeared and MAGENTA was OK as well but wrote it off as a one time event?

Almost leads me to thinking it is a software/firmware issue and not hardware?  Can I swap colors between slots?

[SHThompson]

I've never tried swapping colors between slots on that model so I don't know off hand if they are keyed.

There is also a possibility that the chip on the cartridge will tell the printer what color the cartridge is,  So you might have to swap the chips they are on a small circuit board. You would just move the board with the blob of epoxy on it between cartridges.

[hunkeydorey]

Update: Good news is that last night I reloaded the firmware update 2800_Series_FW_Update-20120307 and selected one of the two available drivers, the HP Color LaserJet 2840 series PCL 6 and it FIXED THE PROBLEM printing from two diffent programs, the config report on the 2840 panel and I went to bed a happy camper; until this morning. It failed again with no yellow. The problem has now turned or always has been INTERMITANT. Another reload of the firmware did not make help.

Another failure mode when ran the config report again, the COLOR (missing all black and all but a very light yellowon the left bar) printed on one page and then the BLACK text printed on the second piece of paper?

By the way, I really appreciate your help and obvious expertise on this off-the-wall issue.

[SHThompson]

When only yellow prints that points to the carousel latch, (aka brake).

When its failing open the top cover and try to move the carousel by hand, the only time the latch should be released is when the carousel is moving.

[hunkeydorey]

Last ditch technical procedure learned at IBM in 1965; pound on it, seemed to work and problem has disappeared again. Thanks for your help. 

[SHThompson]

My dad worked for IBM in 65, and on the 360-65, etc.

Pounding on it probably means the solenoid was sticking, you will eventually have to remove it and clean off some deteriorated foam rubber and replace it with a really cheap thin felt pad.

[SHThompson · Accepted solution]

The solenoid acts as a sound that dampening mechanism and also as a residual.

IBM used the term residual to refer to a thin piece of plastic or rubber material that was between the coil and the arm on a solenoid or relay.

You might know what a residual is but not everybody reading this post will.

[hunkeydorey]

About a month ago, my old old intermittant missing the color yellow reappeared.

All cartridge ink levels are AOK

This week, either the root cause of the yellow issue or a second issue appeared. 

SYMPTOM: INTERMITTANT ALMOST BLANK PAGES.

The very light and patchy colors included yellow, Cyan, etc.

Any suggested diagnosic techniques to get close the problem?

Comes and Goes but pretty solid.