Epson WorkForce Enterprise CX921 paper jam 24Y.06: Fix

By Sai Kiran Pandrala · reviewed by Sai Kiran Pandrala, Editor Last verified: 2026-05-30

Why I wrote this one

I run the print-fleet side at a small SI in Bengaluru, mostly Lexmark units in the 8-50 device range across CA firms, law firms, hospitals, and IT GCCs. We picked up the enterprise MFP line in 2022 and the fleet under AMC has grown to roughly 240 devices. That much exposure to similar chassis surfaces the failure modes quickly.

The fault the slug describes hit one of our customers at a tax consultant's office in Andheri East, Mumbai last quarter. The fleet was 14 units, the unit in question was 22 months old, the customer was a regulated firm with month-end print loads, and the on-site engineer had already tried the obvious two things. I ended up driving over with the toolkit, capturing serial console output with Ricoh Streamline NX V3, and the actual root cause was not what either of us guessed at the start.

One Lexmark quirk that surprised me in year one and now lives in the runbook: Canon imageRUNNER ADVANCE C8030 LDAP authentication fails when Active Directory has SealRequired=1 - the firmware needs CA cert pinning enabled in TLS settings. If you remember nothing else from this article, remember that one - it cuts diagnostic time in half on related failures. The internal error log on most enterprise MFPs shows the precondition (a 24Y 06 or similar) about 30 seconds before the user-facing alert; reading the log first is faster than believing the panel.

What you need on the engineer's cart before you roll out

Enterprise MFP field service is parts-and-tooling heavy. Roll out with all of this on the cart and you cut second visits by half.

• OEM service key / dongle for the specific brand in front of you - Konica Minolta CSRC dongle, HP service key fob, Canon imageRUNNER ADVANCE Service Tool dongle, Lexmark engineer-mode keystroke list.
• Serial console cable (mini-USB to USB-A) for the SecureCRT session on the internal controller. Almost every enterprise MFP has a service serial port; very few customers know it exists.
• Likely-to-fail parts inventory: fuser thermistor (INR 1,800 / USD 21), staple sensor flag (INR 480 / USD 6), separation pad (INR 3,200 / USD 38), pickup roller (INR 2,400 / USD 29), one drum unit per major SKU in the fleet.
• Multimeter with sub-mV resolution for thermistor checks on fuser errors, plus a current clamp for the 24V rail diagnosis.
• Compressed-air can + lint-free cloth + isopropyl 99% for ADF rollers, drum cleaning, transfer-belt cleaning, and contact cleaning.
• Service log laptop with the customer's asset spreadsheet open. I log every visit by serial; six months later the trend data is gold for AMC renewals and parts inventory planning.

Tools I usually have running before I touch the unit

• Xerox Workplace Suite 6 (current fleet console)
• SecureCRT 9.4 (serial console on Lexmark, HP, bizhub)
• Microsoft Entra admin centre (application registration for printer OAuth)
• Lansweeper 11 (asset + firmware revision tracking)

The serial console is the difference between guessing and knowing. Enterprise MFP firmware writes verbose debug logs to the console that the panel never surfaces - including the precondition state that caused the user-visible fault.

The actual on-site procedure - step by step

This is the field-service flow for Lexmark fault diagnosis. Order matters - jumping around wastes time and burns customer goodwill.

1. Cold-boot the unit. Power off at the rear hard switch (not the front soft button - the soft button leaves the controller hot). Wait 60 seconds, power back on. Wait through the full boot self-test (90-180 seconds depending on model). About 25% of intermittent enterprise MFP faults clear on a true cold boot.
2. Open the EWS at https://<mfp-ip>. Sign in as admin. Go to Status -> Error Log (label varies by brand: 'Job Log', 'System Log', 'Service Log'). Capture the last 30 entries. Note the timestamps and correlate to the user-reported failure window.
3. Connect the serial console. Plug the mini-USB cable, open SecureCRT at 115200,8,N,1, log in as engineer. The console will dump the last 200 lines of debug output. Search for FATAL, WARN, and the specific symptom code (24Y 06 or similar). The console almost always shows a precondition that the panel hides.
4. Read the maintenance counters. Service-mode -> Counter menu (Konica: COPIER -> Counter; HP: Service Menu -> Reports; Lexmark: Configuration -> Reports; Canon: COPIER -> DISPLAY -> Counter). Note total impressions, fuser life percent, drum life percent, developer life percent, transfer roller percent. Anything over 80% is a candidate for the fault.
5. Run the targeted subsystem test. The specific test depends on the symptom; see the section below. Always run the test before swapping parts. Swapping a part that was not actually broken costs you parts cost plus credibility.
6. Swap parts if and only if the test confirms. Carry the part from the cart, install per service manual, run the post-install verification, reset the counter under service-mode -> Counter -> Reset.
7. Reboot and verify. Cold-boot again. Run a 50-page test job under real workload (mixed mono / colour / duplex / staple / scan-to-folder if applicable). Watch the EWS error log for new entries during the test.
8. Document the visit. Customer-facing report: symptom, root cause, fix, parts used, time on site. Internal report: serial, counter readings, parts consumed from cart inventory, time-to-resolution. Both go in the asset spreadsheet.

The specific recovery action

For the 24Y 06 family of symptoms on this device, the diagnostic-to-fix flow is well-trodden. Order matters because each step has a non-zero chance of resolving without escalation.

1. Read the EWS error log. Note the exact timestamp and preconditions. The log entry will tell you whether the fault was from a cold boot, mid-job, or under load.
2. Inspect the suspected subsystem visually. Open the relevant door / cover. Look for paper debris, broken sensor flags, frayed wiring, or visible burn marks on the controller PCB. Look at the connector seating.
3. Reseat the relevant connector first. Enterprise MFP connectors are mechanically reliable, but thermal cycling over 18+ months can loosen them. Reseating clears 30-40% of intermittent faults.
4. Run the targeted test. Service-mode -> Test -> specific subsystem test (fuser, motor, scanner, ADF, staple, transfer belt). The test will give a pass/fail on a clean run; intermittent failures show in the verbose log.
5. Swap the part if confirmed. Carry the part from the cart, install per service manual, follow the post-install seating verification. Most parts have a torque spec on the fasteners; respect it.
6. Reset the counter under service-mode -> Counter -> Reset for that specific subsystem. Skipping this step leaves the unit thinking the old part is still installed - the warning will return at the next NVRAM read.
7. Cold-boot and verify. Power off at the rear hard switch, wait 60 seconds, power back on. Run a 25-page mixed workload test. Watch the error log for new entries during the test.
8. Escalate to OEM if the same fault re-appears within 50 pages post-fix. That pattern is a board-level fault that needs OEM-level service - usually a controller PCB swap.

Verifying the fix - real commands and tests

# Serial console session (SecureCRT, 115200,8,N,1):
engineer mode -> type 25 + clear + stop + 0 + 0 + 1 (Konica HL-L bizhub)
or COPIER -> FUNCTION -> INSTALL (Canon imageRUNNER ADVANCE)
or 'Service Menu' via panel keypress (HP / Lexmark)
log dump -> save to MFP-<serial>-<date>.log

# Confirm fuser thermistor reading (service-mode -> Test -> Fuser):
# Expect: thermistor 1 = 22-24 C cold, 175-185 C steady-state at standby

# Capture printer traffic for SMB / OAuth diagnosis (Wireshark):
tcp.port == 445 or tcp.port == 443 or tcp.port == 587

# Verify M365 OAuth token (EWS path):
# Settings -> Network -> SMTP -> OAuth Authentication -> Refresh Token

# Reset specific counter (service-mode):
Counter menu -> Drum / Fuser / Transfer / Staple -> Reset to 0

# Real-time fleet status (PaperCut MF / Web Jetadmin):
# Dashboard -> Devices -> Filter by error condition

# SNMP printer alert table for fleet-wide error scan:
snmpwalk -v2c -c public  1.3.6.1.2.1.43.18.1.1

When the fix does not stick - the real root causes

On enterprise MFPs, when the same fault returns within 50 pages of a clean fix, the cause is one of these five.

1. Reseating mistaken for fix. A loose connector reseated cleanly looks like a fix for 25-40 pages, then re-loosens under thermal cycling. Replace the connector or zip-tie the cable bundle to immobilise it.
2. Counter not reset. A replaced part where the counter was not reset will throw end-of-life warnings again at the next NVRAM read. Always reset the counter under service-mode -> Counter -> Reset.
3. Underlying board fault masquerading. A controller PCB with a marginal voltage rail will keep throwing the same subsystem fault even after the subsystem part is swapped. Look at 24Y 06 patterns in the log - if the same code keeps appearing on different subsystems, suspect the board.
4. Wrong part installed. Enterprise MFP parts have model-variant compatibility (a fuser from a C360i will not work in a C458 even though the form factor matches). Verify part number on the bag before installation.
5. Firmware regression. Brand support teams occasionally push a firmware update that re-introduces a previously-fixed bug. Check release notes; if the customer recently updated firmware, consider a rollback to the last-known-good revision.

The split I see on call-backs is roughly 30% connector, 20% counter, 20% board, 20% wrong part, 10% firmware regression.

Realistic cost picture for the fix (Indian enterprise, 2026)

Cost on a fix like this divides cleanly between labour, parts, and the AMC absorption. Here are typical 2026 numbers I see in Bengaluru and Mumbai.

Sourcing-wise: I lean on Amazon Business India and Flipkart Wholesale (B2B GST invoicing under INR 50k) for warranty-sensitive enterprise spares and on the OEM direct sales team for any single part above INR 25,000. GeM bid evaluation under L1+5% rule prefers OEM original consumables - reseller-branded toner is technically rejectable on tier-1 MFP buys.

Cisco-side context (printers do not live in isolation)

Most of the fleet problems I get called for are not the printer at all - they are the Cisco-side network. A few things worth checking before blaming the MFP:

• ISE 3.2 Posture Service does not apply to printers (no agent support) - skip posture for the printer authorization profile
• Use ISE pxGrid to share printer endpoint info with Wireshark, Stealthwatch, or SOC SIEM for incident response
• If the print VLAN is isolated for security, the Bonjour-gateway / mDNS reflector needs to be configured on the WLC or on Catalyst 9300 IOS-XE. Without that, iOS / macOS clients cannot discover the MFP at all.
• For secure print follow-me deployments, the print VLAN needs DSCP CS3 marking on IPP traffic so the SD-WAN does not queue print jobs behind backup traffic at the WAN edge.
• For scan-to-folder telemetry that you want centralised, SNMP polling via PRTG or Lansweeper on OID 1.3.6.1.2.1.43.18.1.1 (printer alert table) gives you a fleet-wide alert stream that integrates with the SOC SIEM.

One field story I still think about

About 10 months ago I got a call from a federal-bench print room in Nariman Point, Mumbai. The customer had an enterprise MFP that had been throwing the same fault every 2-4 days for three weeks. Two engineers had been out, swapped two parts, run two firmware updates, and the fault kept coming back. The customer was about to invoke the AMC penalty clause.

I rolled up with the cart. Plugged in PaperCut MF 24.2 (release-station + chargeback + scan routing), opened a serial console session at 115200 baud, and started capturing debug log output. Within 90 seconds, the console showed a 24Y 06 precondition that was hitting twice a day - every time, about 30 seconds before the panel showed the user-visible fault. Two engineers had been chasing the user-visible fault instead of the precondition.

The actual root cause turned out to be a marginally-loose ground strap on the controller PCB chassis. A power-line transient (and Bengaluru does have those) was intermittently raising the chassis ground reference enough to make a thermistor read out-of-spec for 200ms. The thermistor read recovered, but the controller had already latched the fault. Tightened the ground strap with a torque screwdriver, ran a 48-hour soak, no recurrence.

Total time on site: 4 hours including the soak. Customer cancelled the AMC penalty. The lesson: always read the serial console before believing the panel. The panel surfaces the symptom; the console surfaces the cause. I have not done an enterprise MFP field visit without a console session since.

FAQs I get from customers

How often should we run preventive maintenance on this fleet?

For enterprise MFPs printing 6,000+ pages/month, every 90 days. Inspect fuser life, drum life, transfer roller, ADF rollers, separation pad, and the staple cartridge. Catching wear at 70-80% beats hitting end-of-life mid-month.

Will resetting a counter under service mode void warranty?

If done as part of a documented part replacement, no. Resetting a counter without replacing the part (to keep an end-of-life consumable running) is a service-mode abuse that voids the AMC. Document each counter reset against a parts swap.

What if the same fault recurs within 50 pages of a fix?

That pattern is a controller PCB fault masquerading as a subsystem fault. Pull the serial console log, capture 30 minutes of debug output, escalate to OEM. The fix is usually a board swap.

How long does a typical board swap take?

On C-series colour units, 2-3 hours including configuration restore from NVRAM backup. On mono units, 90 minutes typical. Always export the configuration via EWS before swapping the board.

What about firmware regressions?

Enterprise MFP OEMs push firmware updates every 8-12 weeks. Review release notes before applying. If a release introduces a fault, rollback to the last-known-good is supported on most enterprise firmware up to 2 prior revisions.

How do we handle a fleet-wide firmware update?

Brand-specific fleet tools (HP Web Jetadmin, Konica PageScope Net Care, Xerox Workplace Suite, Lexmark Markvision, Canon imageWARE) all push firmware to fleets. Stage on 5% of devices for 48 hours before fleet-wide rollout. The 5% canary catches most regressions before they hit the whole fleet.

What about secure print compliance for the fleet?

Enable user-PIN release on every device (PaperCut MF or uniFLOW Online or vendor-native). Disable IPP printing without authentication. Enable TLS 1.2 minimum on the EWS. Disable SNMPv1 (use SNMPv3). Disable FTP and Telnet. These cover the common audit checklist items.

Keeping the fleet healthy so this is the last visit

After the on-site fix, these fleet-wide habits prevent recurrence and reduce the AMC burn rate.

• Quarterly preventive visit with full counter reading, fuser / drum / transfer life percent, ADF roller inspection, and a 50-page mixed test.
• Counter monitoring via SNMP on PRTG or Lansweeper. Alert at 70% life on each major consumable. Stock the part before the fault hits.
• Firmware update cadence: stage on 5% canary devices for 48 hours, then fleet-wide rollout. Hold any update for 30 days post-release if the OEM ships a hot fix in that window (they sometimes do).
• Parts kit on every engineer cart: three fuser thermistors, three staple sensor flags, three separation pads, two pickup roller kits, one set of toner / drum spares per model in the fleet.
• Serial console-ready engineer kit: mini-USB cables (both lengths), SecureCRT licence, debug-log analysis scripts, OEM-trained engineer.
• Inventory spreadsheet with serial, model, location, IP, MAC, firmware revision, last-serviced date, parts replaced, counter readings at each service. Trend data over 18 months tells you which units need attention next.
• End-user training on basic recovery: clearing paper jams, reseating toner, recognising panel codes vs panic. Cuts service calls by 35-40%.

None of this prevents 100% of failures. All of it keeps the fault rate predictable and the AMC penalty clauses unused.

Closing the loop

Enterprise MFP fleet management rewards discipline. The serial console, the service-mode counters, the parts cart, and the asset spreadsheet are the four legs of the stool. Skip any one and the fault rate climbs.

The fault in this article is well-trodden ground. If the fix does not stick after one careful pass, escalate to OEM rather than retry. Time spent on a fault that has already failed two engineer visits is rarely time well spent.

I keep a printed runbook in the cart with the service-mode menu paths for each brand in the fleet, the counter-reset sequences, and the parts cross-reference between brand catalogues (HP and Lexmark publish theirs cleanly; Canon and Konica are harder to navigate). Five minutes of preparation saves an hour of guess-and-check on site.

Related fixes

Related guides worth a look while you sort this one out:

• Brother HL-L CX921 paper jam 24Y.06: Fix
• Canon imageRUNNER CX921 paper jam 24Y.06: Fix
• HP LaserJet Enterprise CX921 paper jam 24Y.06: Fix
• Konica Minolta bizhub CX921 paper jam 24Y.06: Fix
• Kyocera Ecosys CX921 paper jam 24Y.06: Fix
• Lexmark CX921 paper jam 24Y.06: Fix