LG LG-V909DW - Page 69

4. TROUBLE SHOOTING
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To check GSM TX block, there are 4 procedures.
1. Battery Level check
Check if main battery voltage is between 3.6V and 4.2V at C211
2. Power level check at Antenna switch, TP2.
Suppose that UE output power is max
hU GSM850 : 32dBm
iU PCS, DCS : 29.5dBm
3. Power level checking at output stage of Power amplifier
hU To verify whether FEM is okay or not
iU GSM800: check at L200, TP2 (Level : Over 32dBm)
jU GSM HB(DCS, PCS): check at C216 , TP3 (Level : Over 29dBm)
4. Check power level in front of Power amplifier from MDM6200
hU To verify if power amplifier operates well or not
iU GSM800: check at C222 , TP4(GMSK-Typical 13dBm, 8PSK-Typical 6.5dBm)
jU GSM HB(DCS, PCS): check at C212, TP5(GMSK-Typical 12dBm, 8PSK-Typical 5.5dBm)
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FIG 11 GSM Tx Block
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