Epson Printer Error 0x9B — What It Means & How to Fix It

What Does This Error Mean?

Error 0x9B is a critical internal hardware error on Epson printers. The printer has detected a severe fault in its internal components and has shut down to prevent further damage. This error is similar to the well-known 0x97 error and typically points to a main board or printhead failure.

Affected Models

Epson WorkForce WF-3730
Epson WorkForce WF-4730
Epson WorkForce WF-4740
Epson WorkForce WF-7720
Epson WorkForce WF-7710

Common Causes

The printer's main circuit board has developed a fault due to age or a power surge
The printhead has developed an internal short circuit affecting the main board
Ink has leaked internally and reached the circuit board, causing a short
A power spike or voltage irregularity has permanently damaged internal electronics
The printer has been used beyond its rated duty cycle, leading to component failure

How to Fix It

Turn off the printer and unplug all cables — including the power cord and any USB or network connections. Wait at least 5 minutes for all internal components to fully power down.

A complete power disconnect is necessary for a proper reset attempt. Simply pressing the power button is not enough.
Remove all ink cartridges from the printer. Place them on a clean surface with the ink nozzle side up to prevent leaking.

Some users report that removing cartridges during the reset process helps the printer clear this type of error, though results vary.
Hold the power button on the printer for 60 seconds while the printer is completely unplugged. This drains residual charge from the capacitors and ensures a fully clean restart.

Residual charge in capacitors can keep internal components in a fault state even when the printer appears to be off.
Reconnect the power cord only — leave USB and network cables disconnected and leave cartridges out. Turn the printer on and observe whether the error appears immediately.

Testing without cartridges helps determine if a faulty cartridge is contributing to the fault, which is unusual but possible.
If the printer starts without the error, reinstall the cartridges one at a time, turning the printer on briefly after each one. This helps identify if a specific cartridge is triggering the fault.

If the error returns with a specific cartridge installed, try a different cartridge in that slot. If the error persists regardless, the main board is the likely culprit.

When to Call a Professional

Error 0x9B is a serious hardware error that rarely resolves on its own. If the steps below do not clear it, the printer likely needs professional service or replacement. Contact Epson support with your model and serial number — some WorkForce models have known service programs for these types of internal errors.

Frequently Asked Questions

Is error 0x9B the same as 0x97?

They are in the same family of critical hardware errors. Both indicate a serious internal fault, most commonly in the main board or printhead. The troubleshooting steps are identical. The specific error code helps Epson's technicians narrow down which internal component triggered the fault.

Is it safe to keep using the printer with this error?

No — once the printer displays error 0x9B, it will not allow printing. The printer has shut itself down as a safety measure to prevent further internal damage. Do not attempt to force or override the error — it will not work and could cause additional damage.

Epson offered to replace my printer for the 0x97 error. Does that apply to 0x9B too?

It depends on your specific model and when it was manufactured. Epson's extended service programs are tied to specific models with documented issues. Contact Epson support directly, explain the error code, and ask whether your model is covered by any service or replacement program.