Only For Training And Service Purposes - LG TU550 Service Manual

4. TROUBLE SHOOTING
For testing, Max power of UMTS50NHz is needed.
Check Tx SAW
Filter and a solding
of C1105
LGE Internal Use Only
Run a FTM program
set RF mode to
1900B set uplink
fre. to 4135 Click TX
On and WCDMA set
PA range R0 and R1
on set Tx AGC to 430
Check a
YES
current over
500mA?
NO
NO
Check TP4
over -5dBm?
Check PAM block
Refer to 3.5.4
Check TP1
over 25dBm?
YES
Check TP2
over 23dBm?
YES
Check TP3
over 22dBm?
YES
Tx is OK
Check ohter
parts
Copyright © 2007 LG Electronics. Inc. All right reserved.
- 80 -
Check a
NO
Coupler U106
and a solding
of L160
Check a
NO
Duplexer and
a solding of
C1075
Check
NO
ANT.SW
Module U100

Only for training and service purposes