LG 42LK450 Service Manual page 71

Trouble shooting guide
14. USB : movie, music, picture
Check USB Jack(JK1450)
signal differential line
- Jig points under USB jack
ok
Check L401, C405, C410, C489.
Is the voltage 12V?
ok
Check IC401 output.(7/8 pin)
Is the voltage switching?
ok
Check C420.
Is the voltage 5V?
ok
Check IC1450 output.(6/7 pin)
Is the voltage 5V?
ok
Check L1451, C1451
Is the voltage 5V?
ok
Check JK1450 pin1
Is the voltage 5V?
ok
Replace Mstar(IC100) or Main Board.
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Only for training and service purposes
No
Replace Jack
No
Replace L401,C405,C410,C489
No
Replace IC401
No
Replace IC401 block's components
- Refer circuit file
No
Check IC1450 (4 pin)
- Is it high?
No
Replace C1451,L1451
No
Replace JK1450
No
The problem may be caused by
USB device or file in it.
Change USB device.
No
Replace Mstar(IC100) or Main Board.
ok
Check IC1450 (5 pin)
- Is it high?
No
Replace IC1450
ok
The external USB device
may cause over current
problem.
Change USB device.
(memory stick or etc.)
LGE Internal Use Only