LG CU920 - Page 95

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4. TROUBLE SHOOTING
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Check Tx SAW
Filter
Check P AM bl ock
Check c oupler
U102 or U104
Check D uplexer
U103 or FL102
Check F EM FL100
Run a FTM pro gram.
Set RF mode to WCDMA_1900B or
WCDMA_800.
Set Uplink C han to 9400 or 4182
Cli ck Tx ON and WCDMA.
Set PA range R1 On.
Set TX AGC to 400
Check T P6 or TP7
Over -5 dBm?
Check T P2 or TP3
Over 23dBm
?
Check T P4 or TP5
Over 22dBm?
Check TP1
over 25dBm?
YES
YES
NO
NO
NO
NO
YES
YES
YES
NO
Tx is OK
Check other
parts
Check a
Current over
500mA?
Fig. 4.7.1.3 Check Flow of the WCDMA TX Block