LG PX8700 Service Manual page 64

PX8700
4.2.1.2. Check VCTCXO Circuit
Test Point
X101 PIN4 X101 PIN4
VCTCXO VCTCXO
X101 PIN3 X101 PIN3
Circuit Diagram
TCXO Waveform
LG Electronics Inc.
Checking Flow
X101 X101
START START
Check X101 PIN 3 Check X101 PIN 3
Refer to Graph 4.2.12 Refer to Graph 4.2.12
YES YES
Similar ? Similar ?
NO NO
Check X101 PIN4 Check X101 PIN4
NO NO
+2.9V ? +2.9V ?
YES YES
Replace X101 Replace X101
VCTCXO Circuit OK. VCTCXO Circuit OK.
See next page. See next page.
Check U302 Check U302
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