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Flow Chart of Troubleshooting
9-20
9-2-5. GSM Tx
Check U400
pin 6 : 2.8V ?
Check and
change
RFS400,
C408, L402, L403
Yes
Check and
change
U100
,
UCP200
No
CONTINUS TX ON CONDITION
TX POWER DAC : 554 CODE
APPLIED
CH : 62ch
RBW : 100KHz
VBW : 100KHz
SPAN : 10MHz
REF LEV : 10dBm
ATT : 20dB
U401 pin 11 :
about 4~5dbm?
Yes
No
Yes
U401 pin 7 :
3.7V ?
U400
check & change
No
Battery,
U100
check & change
Yes
U401 pin 8 :
1.2V ?
No
U400
check
Yes
U401 pin 6 :
3V ?
No
U100
check
U400 pin 12,13,28,
29 : 2.9V ?
U401
change or resolder
U100
change or resolder
No
Yes
U400
change or resolder
Yes
U401 pin 12 :
about -5dbm?
No
Yes
No
1
2
3
4
5
6
7
8
1
3
2
2
4
5
6
7
8
Check U400
pin 15 : about
2~3 dbm?