LG U250 Service Manual page 82

4. TROUBLE SHOOTING
4.6.2 Checking UMTS PAM Control Block
• PAM control signal
1. PWR_DET : UMTS Tx Power Detected value (Check R120)
2. TX_AGC_ADJ : UMTS RTR6275 Tx Amp Gain Control
3. VREG_TCXO_2.85V : UMTS PAM enable (C170) (about 2.85V)
4. +VPWR : UMTS PAM Main Voltage ( 3V < +VPWR < 4.2V)
5. PA_ON : Turns the PA on and off
6. PA_R0 : Control signals that step the active PA mode and bias
+VPWR
VREG_TCXO_2.85
PWR_DET
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