Samsung SGH-C250 Service Manual page 35

3-2-4. DCS TX
PAM300 pin
12
①
: about 2~3
dBm?
YES
C302,RFS300
③
check&change
PAM300
pin7 : 3.7 V?
YES
PAM300
pin 8 : 1.6V ?
YES
PAM300 pin1
NO
about : -5dBm
?
YES
PAM300
pin 4 : 0V?
YES
PAM300
change or resolder
NO
UCP101
⑤
pinA13,C115
change or resolder
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NO NO
PAM300
pin6 : 2.8 V?
YES
NO
BATTERY
check & change
NO
R303
Check
NO
UCP101
check
U300
④
pin 17 : 2.8V ?
YES
U300
pin19,20 :
26MHz ?
Vp-p : 380mV?
YES
NO U300
pin2,3,22,23:
100mV?
YES
UCP101
change or resolder
U300
change or resolder
UCP101 ②
check & change
NO
OSC300
⑥
change or resolder
3-21
Flow Chart of Troubleshooting
CONTINUOUS TX ON CONDITION
CH : 698CH(DCS)
TX POWER CODE: 520 CODE Aplied
RBW : 100KHz
VBW : 100KHz
SPAN : 10MHz
REF LEV. : 10dBm
ATT. : 20dB