LG KG70c Service Manual page 48

KG70C
Checking Flow Checking Flow
START START
Yes Yes
The voltage at Pin#2 The voltage at Pin#2
Of Q400 is 5.0V? Of Q400 is 5.0V?
Logic level at Logic level at
USB_SEN SE/=Low? USB_SEN SE/=Low?
The frequency of X200 The frequency of X200
is 48M Hz? is 48M Hz?
Check the signal level Check the signal level
at C426 at C426
Is it almost 3.3V? Is it almost 3.3V?
Check the soldering Check the soldering
R409,R410 R409,R410
Is it's state good? Is it's state good?
The USB interface will work properly The USB interface will work properly
If not, Change main board! If not, Change main board!
No No
YES YES
NO NO
Yes Yes
No No
Yes Yes
NO NO
YES YES
NO NO
YES YES
Check the connection of USB cable Check the connection of USB cable
Change the Q400 Change the Q400
Check the soldering of Check the soldering of
X200,R200 X200,R200
The state of that elements is alright? The state of that elements is alright?
Yes Yes
Re-soldering X200,R200 Re-soldering X200,R200
Change the U400 Change the U400
Change R409,R410 Change R409,R410
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No No
Change X200,R200 Change X200,R200