● Code
U1-2117
● Symptom / Cause
The photo sensor is defective or some part is not assembled properly.
● Troubleshooting method
1. Remove the Rear Cover and Duplex Unit. Remove the fuser unit after removing 4 screws.
2. Remove the GUIDE-EXIT LOWER.
To remove it, fi rst, push and release the green lever to the direction of arrow.
Then, lift and pull it.
Service Manual
ML-551x / 651x series
4. Alignment and Troubleshooting
● Error message
Fuser Unit Failure: #U1-2117. Turn off then on
4-120
Samsung Electronics