LG MDD105 Service Manual page 23

ONE POINT REPAIR INSTRUCTION
When you turn on the set, the disc tray won't work.
3-4. IC1
3-4-1. Solution
Replace IC1 ESS8390 on main board.
3-4-2. How to troubleshoot (Countermeasure)
1) Check 5 V CD voltage.
2) Check 3.3 V.
3) Check X501, X100.
4) Check IC100 to IC1 communication resistor R84, R109, R110, R581.
5) Check IC1 to IC502 communication resistor R83, R541, R542.
6) Check ESS8390 SERVO voltage 1.5 V up to snuff instead IC501.
3-4-3. Service hint (Any picture / Remark)
3-8