LG -E450 Service Manual page 125

4.4.2.3 Checking RF signal path (PAM)
START
Check TP1(L124) at U101
Check if there is any major difference referring
To Figure 4.1.1(b). Is any signal detected at that
Check TP2(C135) at U101
Check if there is any major difference referring
To Figure 4.1.1(c). Is any signal detected at that
Is any signal detected at
that point?
PAM is OK. Replace Main B/D
TP3
TP4
TP5
LGE Internal Use Only
point?
Yes
point?
Yes
Yes
R110 1K
1K
R111
1K
R112
No
Check L125,C105, L124, SW101
No
Check TP3(R110),TP4(R111), TP5(R112),,
at U101. Is any DC signal detected
No
Check C135
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4. TROUBLE SHOOTING
at that points?
Yes
Replace U101
The Problem may be Logic part
Refer to Logic troubleshoot
ANT_SEL0
ANT_SEL1
ANT_SEL2
Only for training and service purposes
No