Samsung SGH-A500, Service Manual, Page: 23 / 31

SAMSUNG Proprietary-Contents may change without notice
6- 8
SGH-A500 Flow Chart of Troubleshooting and Circuit Diagrams
10. GSM transmitter
U201
PIN
7&19=2.8V?
U201
PIN25=1.6~
1.8Vpp?
OSC101
PIN6>9
dBm(902.4MHz
)?
F101
PIN3>8
dBm(902.4MHz
)?
U103
PIN10=22~24d
Bm(902.4MHz)
?
F103
PIN5=22~24
dBm(902.4MHz)
?
U101
PIN8=22~24dBm(
902.4MHz)?
CN101 CHECK/
CHANGE
YES
YES
YES
YES
YES
YES
YES
U601
CHECK/
CHANGE
OSC202
PIN3>13MHz
2.5Vrms?
OSC201
PIN1=(1326.4
MHz)-3~3
dBm?
U201
PIN28>-10
dBm(902.4M
Hz)?
U201
CHECK/
CHANGE
NO
YES
YES
YES
OSC101
PIN5=2.8V?
OSC101
CHECK/
CHANGE
F101
CHECK/
CHANGE
YES
NO
U103
PIN6&8=
3.4~4.2V
?
U103
PIN14=
1.5~1.9V
?
U103
PIN16=
0~0.5?
U103
CHECK/
CHANGE
F103
CHECK/
CHANGE
U101
PIN2=0~0.5V
&PIN11=2.5~
2.8V?
U101
CHECK/
CHANGE
NO
NO
YES YES
NO
NO
NO
NO
OSC202
PIN4=2.8V?
O S C 2 0 2
C H E C K /
CHANGE
U601
CHECK/
CHANGE
NO
NO
YES
OSC201
PIN7=2.8V?
O S C 2 0 1
C H E C K /
CHANGE
U601
CHECK/
CHANGE
YES
NO
NO
OSC101
PIN6>9
dBm(902.4
MHz)?
F105
CHECK/
CHANGE
NO
NO
YES
OSC101
PIN5=2.8V?
O S C 1 0 1
C H E C K /
CHANGE
U601 CHECK/
CHANGE
NO
YES
BATTERY
CHECK/
CHANGE
NO
NO
CON101
PIN1=22~24
dBm(902.4MHz)
?
ANT1
CHECK/
CHANGE
YES
NO
U104&U105
CHECK/
CHANGE
NO
YES
U104&U105
PIN4=2.8V
?
U601
CHECK/
CHANGE
NO
YES
U201
CHECK/
CHANGE
YES
U102
PIN10=2.8V
?
U601
CHECK/
CHANGE
NO
YES
NO
U102
PIN5>902.4
MHz(-28dB
m)?
F104
PIN4>902.4
MHz(-18dB
m)?
YES
F103
CHECK/
CHANGE
NO
F104
CHECK/
CHANGE
NO
U102
CHECK/
CHANGE
YES
CONTINUOUS Tx ON
CONDITION
CH : 62
Tx POWER LEVEL : 10
RBW : 300KHz
VBW : 300KHz
ATT. : 30dB