All Bd Disc" Reading Error - LG BD550 Service Manual

2. "ALL BD DISC" READING ERROR

- All the Blu-ray disc is not operated, but DVD and CD are operated normally.
- If the LDO for APC of BD laser diode is abnormal, BD doesn't work.
- If the LD current control is abnormal, BD doesn't work.
2-1. Component
1) MD (Traverse Assembly)
2) IC707 – Adjustable LDO
2-2. How to troubleshoot (Countermeasure)
1) Check MD (Traverse, pick-up) first of all
2) Check input/output voltage of LDO IC707 – (12V, 8.1V)
3) If output voltage is abnormal, check the periphery of IC707 and replace it.
4) Check the BD LD Control input/output.
If input signal (LTHR_LPF) is ok But no output (LDI_BD), Check the TR Q714,716
2-3. Service hint (Any picture / Remark)
INPUT(FROM MAIN CHIP)
LTHR_LPF
2010
COMPONENT REPAIR GUIDE
8.1V
OUTPUT(TO PICK-UP)
4-3
12V