![background image](http://html.mh-extra.com/html/samsung/sgh-e840/sgh-e840_service-manual_1190649042.webp)
Flow Chart of Troubleshooting
3-27
3-2-6. GSM900 Transmitter
F100
pin 6 : 2.8V
CONTINUS TX ON
CONDITION
MS TX level 19
CH : 62
RBW : 100KHz
VBW : 100KHz
SPAN : 10MHz
REF LEV. : 10dBm
ATT. : 20dB
UCP300
check &
change
2
NO
NO
YES
PAM100 pin7
3~6dBm?
YES
F100, C100
check & change
NO
1
PAM100/R105
check & change
YES
3
PAM100 pin 4 : 3.7V
NO
BATTERY, BATTERY CONNECTOR
check & change
4
YES
PAM100 pin3: 'LOW'
NO
5
UCP300
check & change
YES
6
UCP300
check & change
PAM100
pin 1: 'HIGH'
NO
YES
PAM100
pin 6 : 1.2V
?
NO
YES
NO
PAM100 pin
12
: -5dBm?
YES
PAM100
change&resolder
7
U104
pin31 :
7~11
dBm?
U104
pin17 13MHz
Vp-p :950mV
U104
change or
resolder
U104
pin27,28,29,30
1.7V
U104
check &
change
C108
change or resolder
OSC100
pin 3 : 13MHz
Vp-p : 950mV
OSC100
change or resolder
U104
change or
resolder
NO
NO
NO
YES
YES
YES
NO
YES
NO
8
UCP300
change
9
10
11
F100 pin 8
about
2~5dBm?