LG FM300 Service Manual page 51

voltage(TP1) TP1= 1.2V
(2) Check TX_PLL voltage(TP2)
(3) Check DCDC Output
voltage(TP3) TP3= 1.5V
(4) Check 1.2V_RF voltage(TP4)
FM300 working well ! FM300
LGE Internal Use Only
U506
TP1
CHECKING FLOW
(1) Check RX_PLL
Yes
TP2= 1.2V
Yes
Yes
TP4= 1.2V
Yes
ki ll !
4. TROUBLE SHOOTING
U502
U508 U508
TP2
U507
No
Check the R538 Soldering
If soldering is fine, change U506
No
Check the R540 Soldering
If soldering is fine, change U507
No
Check the R546 Soldering
If soldering is fine, change U508
No
Check the R511 Soldering
If soldering is fine, change U502
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4. TROUBLE SHOOTING
TP4
TP3
Only for training and service purposes