Gsm Receiver - Samsung SGH-X550 Service Manual

Flow Chart of Troubleshooting

9-12. GSM Receiver

RX ON
RF input : 62CH center freq : 942MHz
Amp : -50dBm
Yes
DUF200 Pin8
>= -65dBm
Yes
DUF200 5,6
>= -68dBm
Yes
U101
pin 29 >= -70dBm
pin 30 >= -70dBm
Yes
U101 pin 6,7,8,9
>= 1V
Yes
Check U500
END
No
Resolder RFS200,C203,L201
No
No
Resolder L101, L102, L103
No
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Check DUF200
pin10,pin12 = L
Yes
U101 pin
10,15>=2.8V
Yes
9-20
No
Check ANT Switch
control circuit
Resolder DUF200
No
Check & Resolder
U101, OSC100
RF26MHz, RF PSU Part
Resolder U101