LG LX-D2560A Service Manual page 58

I USB PART
TURN ON USB
YES
"Searching "or
"USB "Display
check
YES
Reading OK check
YES
OK
NO
NO
Check the USB JACK POWER supply.
(Check DATA LINE PIN 14~17,20~23)
- 4-7 -
Check the POWER supply circuit.
(Check P5701)
YES
Check the HRST#signal
YES
Check the USB PART
and DVD PART line.
(Check P4302)
YES
Check the USB DATA LINE.(P4302)
YES
Check the IC405 (UBI9021).