Michael and Yuhang

After pointing out the place where issue appears in elog2916, we followed the suggestion from Pierre and checked the resistor connect through J10.

1. We disconnected three pins of J10.

2. We put resistor meter between these pins. It was found that the resistor between blue and black wires becomes infinity after touching wires.

3. We peeled off the heat shrinkable tubing for black wire at the place of connecting to potentiometer. But no issue was found.

4. We peeled off the heat shrinkable tubing for blue wire at the place of connecting to potentiometer. We found the inner steel part of the wire has broken.

5. We soldered the broken blue wire.

6. We tested OPO locking servo and found it worked again. But we will see if it always work in the next week or so to confirm its recovery.