Samsung Multifunction Printer Error Code #04-000

The #04-000 error indicates a Polygon Motor Error, meaning the LSU (Laser Scanning Unit) motor has failed to operate or reach its required rotational speed. This motor drives the spinning polygon mirror that deflects the laser beam to form print images. The printer stops all operation when this error is detected to prevent damaged output or internal harm. The LSU assembly or its signal circuit must be inspected to resolve it.

A power cycle or reset may temporarily clear the error display, but if the underlying polygon motor fault is still present, the error will return as soon as the printer attempts its next print job. A reset alone does not repair a failed motor, a broken harness, or a faulty control board circuit. The root cause must be addressed for the printer to return to normal operation.

Repair costs vary depending on the failed component. If the fix is a reseated or replaced wiring harness, costs may be relatively low, generally in the range of $20 to $80 for parts and labor. Replacing the full LSU assembly typically costs between $80 and $200 depending on the printer model and parts availability. If the main control board's motor driver circuit has failed and a board replacement is needed, costs can range from $150 to $350 or more, at which point evaluating repair versus replacement of the printer may be worthwhile.

Some basic checks are within reach of a knowledgeable DIYer, such as inspecting and reseating the wiring harness connectors leading to the LSU assembly. However, if the polygon motor itself has failed or the motor driver circuit on the main board is faulty, replacing the LSU assembly or the main board is required, and these repairs are best handled by a technician familiar with laser printer internals. Attempting to open the LSU assembly itself is not recommended, as it is a sealed optical unit.

The printer will not allow normal printing while this error is active, which prevents unsafe or incomplete operation. You should not attempt to bypass or force the printer to operate while this fault is present. Leave the printer powered down until the LSU motor fault has been diagnosed and repaired.