LG CJ87 Service Manual page 38

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.
3-5. DSP (IC501)
3-5-1. Solution
Please check and replace IC501 on MAIN board.
3-5-2. 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.
2) If below bootstrap waveform doesn't come out, then replace IC501(DSP IC).
3-5-3. Service hint (Any picture/ Remark)
IC501 IC501
< MAIN board top view >
ONE POINT REPAIR GUIDE
R578
PGPB07
(YELLOW)
R598
PAD19
(GREEN)
R597
PAD20
(PINK)
< Bootstrap waveform >
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