Samsung SGH-X300 Service Manual page 25

2-2-5. DCS/PCS Tx
Check U101
pin 15 : about
2~3 dbm?
Yes
1
Check and
change
CN100, L100
U102 pin 7 :
3.7V ?
U102 pin 8 :
1.2V ?
U102 pin 12
about -5dbm?
U102 pin 6 :
3V ?
U102
change or resolder
No
Check U101
pin 6 : 2.8V ?
Yes
No
U102 pin 11 :
about 4~5dbm?
Yes
U101
check & change
No
check & change
Yes
No
Yes
No
:
Yes
No
U200
Yes
SGH-X300 Flow Chart of Troubleshooting
2
Check and
No
change
U300,U200
3
4
Battery, U200
4
U200 check
4
check
U101 pin 12,13,
28,29 : 2.9V ?
Yes
U101
change or resolder
2-21
CONTINUS TX ON CONDITION
TX POWER DAC : 560 CODE
APPLIED
CH : 698CH(DCS),
660CH(PCS)
RBW : 100KHz
VBW : 100KHz
SPAN : 10MHz
REF LEV : 10dBm
ATT : 20dB
No
U200
change or resolder
3
4