Dell 5110CN printer won't print black

Does the same thing happen when you try to print a settings page?

(are you on warranty)

Yep.  Black tries to print but only colors are fine.  I was thinking perhaps it was the Toner Dispenser Assembly or the Black Developer Assembly but wanted to check to see if anyone else had seen this issue.

Printer is no longer under warranty.

/John 

Let's check the mag roller on the black developer first. Remove the drum assy and look at the black mag roller surface. Does it appear lightly coated? (compared with the others?)

If so, the toner supply to the devleper is likely depleted.

Let's run a special diag to manually run the toiner motor.

First, POWER OFF the printer and remove the power cord.

To remove the right side cover.

1. remove toner carts

2. top toner bezel comes off next (2 screws on each front corner under the drum cover 2 release clips, inside back)

3. 1 screw inside the top back of the cover at the rear; 1 latch clip at the lower front

4. Close all doors and put the toner carts back in.

You should see the 4 toner dispenser motors along the top right side underneath the ends of each cart. The black motor is of course, the one at the rear.

*CAUTION* Immediately below the toner motors is the main power supply. The big metal heat sinks are LIVE and will give you a surprise if you touch them when the power is on.

Second, plug the power cord back in.

1. Press and hold the UP and DN arrow keys while powering on the printer; the buttons may be released when the LCD indicates "Diagnosing"
2. LCD should indicate "Customer Mode" and "ESS Diag"
3. Press the DN arrow to display "IOT Diag"; press the ENTER button
4. LCD should indicate "IOT Diag" and "Digital Input"
5. Press the DN button once and press ENTER to select "Digital Output"; the LCD should indicate "Digital Output" and "DO- 0 Ready"
6. Repeat pressing the UP button until "DO- 4e" is shown, then press the ENTER button to execute the test.

Examine the black toner motor's shaft to see if it's rotating. You can place your finger on the end off the shaft if you're not sure. Don't run this too long.

If it IS rotating, we next need to ensure the auger inside the toner supply tube is rotating.

Again, power off the machine and pull the cord again.

Remove the rear cover enough to see the black supply tube (don't disconnect the fans)

Run the test again to see if the auger is moving inside the supply tube. Don't run this too long.

That's enough for now...... Let me know what you found.

Thanks for your help and the speedy response Llynster.

Went through your steps and discovered that the motor shaft IS rotating, but the auger gears in the back seem pretty much stuck.  It coincidentally makes a fairly ugly noise because of this.  I could manually turn the gears a couple of rotations using my finger.  But when I rerun the test, they spin what seems to be a number of equal turns and freeze back up.

What's next? 

Well since I was reluctant to order some replacement parts, I applied a bit of old fashioned ingenuity. I just kept manually working at the gears, spinning them repeatedly with some decent force, basically to try to free up any clogs or debris.

It worked!

Thanks again for the lead on where to start and all the help. Problem solved.

I suspect the toner motor pinion gear has chewed a bare spot in the next gear reduction. That's the only  thing I can think of since you say the motor does spin, but the gears don't, unless you give them a nudge but they soon stop.

Something's jammed.....

It's a pretty messy job, but you could remove the toner motor and supply tube, empty the tube out and try'n find out what's causing the jam.

If you decide to do this, I might recommend doing this on top of a high thread-count (so the toner don't filter thru) sacrificial sheet that will catch all the loose toner.

BE CAREFUL if yu use a vacuum cleaner. Toner particles can damage the motor in the vacuum if not protected by a micron type filter.

If you can find someone at Dell to sell you the part, the part number is TF123; the Toner Dispenser Assy. This includes all 4 motors, auger tubes, etc

That's Great..... glad it worked.

Can you do us a favor and review the Accepted Solution thread?

"skewed about 1/4"

Can you explain? Any pictures?

We replaced the Toner Dispenser Assembly with Dell part # TF123.  However, the new assembly is skewed about 1/4" so you can't insert toner cartridges back in.

We are bringing the printer in for Depot maintenance at this point to further check it out.

/John 

Thank you so much for the tips.  Took me about an hour to disassemble and reassemble but the printer is now printing black.  Both the toner gear and the auger seemed to be spinning but I just wiggled the toner hose a little and heard and felt the auger turning.  I did have a non-Dell black toner cartridge inserted so it may have clogged things up, just not sure.  I'm going to insist that we buy Dell toner to avoid the risk.