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This error for this model printer is a CR Encoder check error. The printer causes this error and stops operation if it cannot detect the encoder pulse signals at intervals of the specified time during the power-on initialization operation or while the CR Motor is driving.
This is caused by the CR Encoder FFC being disconnected, the CR Motor connector is disconnected, the FFC of the encoder on the CR side is broken, the wiring of the A and B phases are wrong (opposite), the wiring of the CR Motor is wrong (opposite), the CR Motor shorted out, or the fuse for the motor driver is blown. (on the Main Board)
You might be able to fix this by reattaching the Timing Fence for detecting the encoder securely and correctly.
If that doesn't work, clean dirt or paper dust on the Timing Fence and check if it is damaged.
If that doesn't remedy, reconnect the CR Encoder FFC or the CR Motor connector securely.
If it is still not working, execute the CR Timing Belt Tension Adjustment
After that, if still not fixed, replace the CR Encoder Sensor.
After that and it is still not fixed, try replacing the CR motor assembly.
Finally, you'd have to replace the main board assembly.
To answer your first question, I have included a picture to help you identify both the CR unit and the carriage locking tab. It may not be the exact model but it will help you nonetheless.
I hope this helps. If you need further assistance, reply and I, or another expert, will answer you in an timely fashion.
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