LG LG-H815 - 3. Trouble Shooting; Checking XO Block

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3. TROUBLE SHOOTING
The output frequency(19.2MHz) of XO(X4100) is used as the reference one of WTR3905 and PM8994 internal VCO
3.1 Checking XO Block
Image Checking Flow
Check TP1
Is it 19.2MHz?
START
The Problem may be
Logic part
Refer to
Logic trouble shoot
Replace X4100 and then
check TP1
Is it 19.2MHz?
XO Circuit is OK.
Check next step
XO Circuit is OK.
Check next step
NO
NO
YES
YES
BOTTOM
U1500
TP1
Circuit Diagram
TP1
1212