Lexmark MS821 140.84A & 149.80A Motor Errors: Fixes & When to Replace

PRGPRG Technical Team·Updated July 2026Error-Code Guides·7 min read

From 1,400+ Lexmark repairs across our network, motor-related error codes are a recurring pattern — and on the MS821 series, two codes in particular generate the most confusion: 140.84A (service transport motor) and 149.80A (redrive motor). Both can look like a parts failure when they're often a firmware problem. This guide explains what each code actually means, the right diagnostic sequence, and how to know when you genuinely need a replacement motor.

The short version

140.84A is a service transport motor fault; 149.80A is a redrive motor fault — both live in the paper-path drive system.
At lower page counts, a firmware flash or extended cold reset clears both codes without any parts replacement.
At high page counts (200,000+), the same codes point to genuine mechanical wear — firmware alone won't hold.
Always flash firmware and perform a cold reset before ordering a motor; it's the fastest, cheapest first step.

Network-level Lexmark service data; motor-error resolution split reflects technician-documented outcomes across the MS-series.

What 140.84A and 149.80A Actually Mean

Lexmark's error-code numbering follows a consistent pattern: the first three digits identify the subsystem, and the two digits after the dot identify the specific fault type. On the MS821:

140.84A — Service transport motor error. The engine controller expected a signal from the transport motor encoder but didn't receive it within the allowed window. The printer halts and logs the fault.
149.80A — Redrive motor error. The redrive assembly — which pulls paper from the main paper path into the output area — reported a motor-not-ready or motor-stall condition. This one sometimes self-clears after a full power-off cycle because the motor controller resets its internal state.

Both motors sit downstream in the paper path. When either stalls or fails to reach speed, the engine controller throws the corresponding error to prevent a paper jam cascade. For a deeper look at how the paper path interacts with these drive systems, see our guide on why laser printers get paper jams.

Firmware Problem vs. Mechanical Wear: How to Tell the Difference

This is the core diagnostic question. The MS821's engine firmware governs motor timing sequences, encoder tolerances, and fault thresholds. Early firmware builds had known issues with motor-timeout windows — the controller would declare a fault before the motor had a fair chance to reach operating speed, especially in cold environments or after prolonged idle periods.

Signals that firmware is the root cause:

Page count is below ~150,000 total impressions.
The error appeared suddenly with no history of paper-path noise or grinding.
The code clears after a cold reset (full power-off for 60+ seconds) and the machine prints normally for a period before returning.
You're running firmware older than the current release on Lexmark's support portal.

Signals that mechanical wear is the root cause:

Page count is north of 200,000 impressions — well past the rated maintenance interval.
You can hear bearing drag, grinding, or inconsistent motor spin-up during the warm-up cycle.
The error is persistent: it returns within a few print jobs even after a firmware flash and reset.
The drum unit and fuser are also showing end-of-life symptoms.

One documented MS821n in our service history illustrates both scenarios: at 214,446 pages, the unit was throwing 140.84A persistently. A firmware update cleared the fault, but the drum had also reached end-of-life and was replaced during the same visit. The firmware fix was necessary; the drum replacement addressed the underlying mechanical wear that was stressing the transport system.

Step-by-Step Diagnostic Sequence

Follow this sequence before touching any hardware:

Cold reset first. Power off the printer completely. Unplug the power cord from the wall — not just the printer. Wait 90 seconds minimum. Power back on and run a test print. If the error doesn't return in the first 10–15 pages, firmware is the likely culprit and you may have a simple fix ahead.
Check firmware version. Print a menu settings page (Settings > Reports > Menu Settings Page). Note the firmware version string. Compare it against the current production build on Lexmark's support portal for the MS821.
Flash the firmware. Download the correct firmware package for the MS821 (not MS822 or MS826 — confirm the exact model). Flash via the Lexmark Web GUI (go to Settings > Device > Update Firmware) or via USB drive. The printer will reboot automatically.
Perform a post-flash reset. After the firmware flash, power cycle the unit again with a full 60-second cold reset. This clears any cached motor-state data that could persist through a soft reboot.
Run a long print job. Print 50+ pages continuously. Monitor for error recurrence. If the code doesn't return, you're done.
If the code returns, inspect the paper path. Open all access doors and manually rotate the transport and redrive assemblies by hand. They should spin smoothly with light resistance. Drag, grinding, or a locked-up feeling indicates a worn or failed motor/gear assembly.
Check the drum unit. On high-page-count units, a worn drum can increase drag on the transport system enough to trigger motor errors. If the drum is past its rated yield, replace it and retest before condemning the motor.

Parts Involved When Mechanical Replacement Is Required

If the firmware path doesn't resolve the issue, these are the likely replacement items:

140.84A — Transport motor assembly. This is typically a DC motor with an encoder disk. On the MS821, it's accessed from the left-side drive assembly after removing the left cover panel. Expect roughly 45–60 minutes of labor for a clean swap.
149.80A — Redrive motor / redrive assembly. The redrive motor is smaller and sits near the output area. In some cases the entire redrive assembly (motor + rollers + frame) is replaced as a unit rather than the motor alone, since the rollers are often worn by the same page-count threshold.
Drum unit (imaging unit). On high-mileage machines, replace as part of the same service call. Running a fresh motor against a failing drum just shifts the load.
Main drive gears. Inspect the gear train connecting the motor to the paper path. Stripped or worn gear teeth cause motor stall events that look identical to motor failures. If the motor checks out mechanically, trace the gear train before ordering a replacement motor.

When It's Time to Call a Technician

The firmware-flash sequence above is something a capable IT admin can handle. Once you're past that and the error persists, the diagnosis shifts to physical inspection and parts replacement — and that's where it makes sense to bring in a technician. Disassembling the left-side drive assembly on the MS821 without the right procedure risks cracking mounting tabs and misaligning encoder positions, which turns a motor replacement into a much larger repair.

The error returns within 20 pages of a firmware flash and cold reset.
You can hear mechanical drag, grinding, or stuttering during warm-up.
Page count exceeds 200,000 and the unit hasn't had a scheduled maintenance kit service.
The code alternates between 140.84A and 149.80A — this suggests a main drive issue affecting multiple motors rather than a single motor failure.
The error appears alongside paper-path jams — especially if those jams are occurring downstream near the output bin, which is redrive territory.

Our field technicians service the MS821 on-site and carry the common Lexmark drive components. You can schedule a visit through our printer repair service page. We'll confirm the root cause before ordering parts — no guessing, no unnecessary replacements.

Root causes across Lexmark MS-series motor-error calls in our network — causes can co-occur; percentages reflect share of cases, not a single-total partition.

Frequently asked questions

Can the 149.80A error really clear itself without any action?

Yes. The redrive motor controller stores a fault state in volatile memory. A full power-off cycle resets that state. If the underlying cause was a momentary stall — from a cold environment, a brief paper-path obstruction, or a firmware timing issue — the error won't return. If the motor has actual wear, the code will return within a few print cycles.

Does the MS821dn have different motor codes than the MS821n?

The motor error codes (140.84A and 149.80A) apply across the MS821 series — n, dn, and adn variants. The drive assembly layout is essentially the same. the dn and adn models add a duplex unit, which has its own motor codes in a separate range, but the transport and redrive codes are shared.

Is the MS821 firmware the same as the MS822 or MS826?

No. These are different firmware packages even though the printers share industrial design elements. Always verify the exact model string on the printer's menu settings page before downloading firmware. Flashing the wrong package can brick the formatter board.

How long does a firmware flash take on the MS821?

Typically 8–12 minutes from upload to completion. The printer will be offline during the flash and will reboot automatically. Don't power cycle it manually during the update — interrupted firmware flashes can corrupt the firmware partition and require a board-level recovery.

What's the rated page life of the MS821 transport motor?

Lexmark doesn't publish a standalone motor-life rating, but the maintenance kit interval for the MS821 is 300,000 pages. Motors are designed to outlast the maintenance interval under normal duty cycles. If you're hitting motor failures before 200,000 pages and firmware isn't the cause, investigate environmental factors: excessive dust, paper dust buildup on motor vents, or unusually heavy paper stock that increases drive load.