A Deeper Dive into Xerox WorkCentre 7120 Series WC 7120, 7125, 7220, 7225

In prior articles, we’ve covered the drum cartridges and fusers for this series of full-color MFP copiers. Now let’s see what makes these machines tick—we’ll cover the Fault Code meanings and take a first stab at how to get around in diagnostic mode.

As a refresher, these machines are designed for office use with a duty cycle of around 50K impressions per month. They’re price at around $7,000 new, which is roughly half the cost of a WC-7855. Although they’re not as heavy of a machine, they’re capable of producing fine-looking full-color copies and prints, and are substantial machines in their own right.

This series has a duty cycle of around 50,000 impressions per month, with toner cartridges expected to run about $15,000 (for c/m/y) and $22,000 (for black) assuming 5% coverage. One thing to note is that there is more than one region or “plan.” If you install the wrong version, the machine will reject it because the Customer Replaceable Unit Monitor (CRUM) chip is wrong. There are 4 drum cartridges (R1-R4) which are color specific, as each includes the developer station underneath it. These have a stated yield of around 50-60,000 each (part numbers: 013R00657(K), 013R00658(Y), 013R00659(M), 013R00660(C)). Replacement parts for the drum cartridges and drum count reset CRUM chips are available to repair, rebuild or otherwise extend the yield on these cartridges.

The 2nd BTR (Transfer Roll Assembly) on the left door is R5, good for just under 200,000. There’s also a Transfer Belt Unit (R6) which is fairly easy to replace; it’s considered to be customer replaceable, and has a stated yield of 200,000. Finally, there’s the Toner Waste Container (R7), which comes with a new wand (stored in the front door) for cleaning the ROS windows (the laser-slit glasses). To clean the ROS windows, remove the Waste Container first, and behind there you’ll see the slots where you can slide the wand in and out. Push the wand in slowly until it stops, then retract it slowly for best results.

Next, let’s have a look at some of the fault codes. This list is by no means complete, but should send you in the right direction for most of the common faults. In the list below, some of the hints tell you to “power off completely,” which means turning off the outer power switch first (that one on top of where the front door opens on the right). After the machine is fully powered down, you then need to open the front door to turn off the Inner Main Power Switch on the inside of it.

For reference, here are some acronyms used repeatedly in the fault list:

ATC = Automatic Toner Concentration
ADC = Automatic Density Correction
CRUM = Customer Replaceable Unit Monitory (drum or toner chip)
ESS = Electronic Switching System (the print controller board on the machine)
MCU = Main Control Unit (main board)
NVM = Non-Volatile Memory (machine settings)
ROS = Raster Output Scanner (laser unit)

Note: a handful of fault codes require you to reset NVM settings back to zero before the machine will run again. See the asterisks at the bottom of the table for more info about resetting the fault codes which require the extra step.

FAULT CODE LIST

For 7220/7225, the fault codes will all start with “3” instead of “0.”(e.g. 310-319 = 010-319)

*Faults requiring reset from NVM Read/Write

Some codes require setting a particular NVM code back to “0” to clear the fault. Enter diagnostic mode and choose “NVM Read/Write” reset the value of the specified code back to “0” (read more below).
*010-319/010-320/010-333/010-337 fuser faults—reset NVM code 744-248 back to “0”
*092-312 Yellow toner dispense fault—reset NVM codes 752-365 & 752-369 back to “0”
*092-313 Magenta toner dispense fault—reset NVM codes 752-366 & 752-370 back to “0”
*092-314 Cyan toner dispense fault—reset NVM codes 752-367 & 752-371 back to “0”
*092-315 Black toner dispense fault—reset NVM code 752-368 & 752-372 back to “0”

**Faults requiring reset from dC135 HFSI (high-frequency service items)

1. Entering Diagnostics Mode
Hold down “0” for at least 5 seconds
2. While holding “0,” press “Start”
A passcode screen shows up, enter “6789” and touch “Confirm”
Press “Machine Status” and choose the “Tools” tab
3. Choose “System Settings,”
4. In the center ”group” column, choose “Common Service Settings”
5. In the right column (features), scroll down to “Maintenance/Diagnostics” and choose “NVM Read/Write”

*NVM Read / Write (Memory Settings)

To reset some fault codes:
Enter diagnostics mode and touch “NVM Read/Write”
Enter the NVM code (chain-link code) and touch “Confirm/Change” (t will show you the “Current Value”)
Enter a “0” in the “New Value” column and touch “Save”
Select “Close” and finally “Exit” diagnostics
The machine will need to reboot for the NVM changes to take place and for the machine to attempt to come to ready again, now that the fault code has been cleared.

**HFSI Counter Resets

The CRUs should automatically reset when the customer installs the assembly, but the product manual also presents a way to access HFSI counters from diagnostic mode. This may be helpful if a new module fails to reset properly. After you enter Diagnostics Mode (read above):

• For the 7220/7225: press “Service Info” or the “Maintenance” tab and choose “Dc135 CRU/HFSI Counters.” Scroll through the list, choose the HFSI item and touch “Reset Counter.”
• For the 7120/7125: enter diagnostics mode, choose “Adjustment/Others,” then select “HFSI Counter.” Select the HFSI from the list and press “Details,” followed by “Reset Current Value.”

Special Boot Modes

This is helpful for clearing jobs when they get stuck in the queue. Hold down the buttons specified below while turning on the power, and keep holding them until the boot screen (progress bar) appears.

Job Log Initialize: hold down “1,” “Stop,” and “Energy Saver” buttons while powering on.

Spool Log Initialize: hold down “6”, “Stop,” and “Energy Saver” buttons while powering on.

HDD (hard drive) Initialize: Hold down “4,” “Stop,” and “Energy Saver” buttons while powering on (WARNING: all customer data will be deleted if you do this. Make sure to create backups of all data set before you initialize the HDD)

Now that we’ve scratched the surface on this series of machines, hopefully they will be more approachable for everyone. Happy repairs.