LG CM9730 Service Manual page 27

NO BOOTING IN CD/USB FUNCTION
After you turn on power key and displayed message in the following order
(HELLO --> VOL XX --> CD or USB) on VFD,
it will not display other message on VFD, and it will not boot-up normally.
4-5. DSP IC (IC501: MLC3700A)
4-5-1. Solution
Please check and replace IC501 on MAIN board.
4-5-2. How to troubleshoot (Countermeasure)
1)After check them by previous pages about NO Booting, if the set is still no booting,
Check soldering status of IC501.
Check boot strap option (R598, R594, R597) of IC501(DSP IC).
2) If below bootstrap waveform doesn't come out, then replace IC501 (DSP IC).
4-5-3. Service hint (Any picture / Remark)
R546
IC501
< Signal check point >
ONE POINT REPAIR GUIDE
R594
PGPB12
(Yellow)
R598
PAD19
(Green)
3-10
R597
PAD20
(Pink)
< Bootstrap Waveform >