Service manual

4. Alignment and Troubleshooting

Service Manual

ML-551x / 651x series

4-132

Samsung Electronics

 Code

U2-1111

 Error message

LSU Unit Failure: #U2-1111. Turn off then on

 Symptom / Cause

LSU motor does not work normally.

1. Harness connection error.

2. LSU is defective.

3. Main board is defective.

 Troubleshooting method

Check the followings.

1. Execute the LSU motor test in EDC mode. Check LSU motor operation sound.

2. If there is no sound, remove the right cover. Check if the C9 or C10 connector is connected

properly (Picture-ᐭ).

3. It it is OK, remove the top cover. Check if the LSU connector is connected properly.

(Picture-ᐮ).

4. Check if the LSU harness is defective. (Picture-ᐯ)

5. Reconnect the LSU harness and then execute the LSU motor test again.

6. Replace the LSU.

7. If the problem persists, replace the main board.