Samsung SGH-600 Service Manual page 22

Troubleshooting
5-1-2 TX Power Problem
CH.60 (902 MHz) &
Tx Carrier ON (Power level 5)
F201 Input ≥ - 10 dBm?
Yes
F201 Output ≥ -15 dBm?
Yes
U202 Input ≥ - 15 dBm?
Yes
U202 Output ≥ 30 dBm?
Yes
U204 Input ≥ 30 dBm?
Yes
U204 Output ≥ 30 dBm?
Yes
I/F Connector pin 21
≥ 30 dBm?
5-2
RF VCO
≥ -10dBm(1172MHz)?
No
IF VCO ≥ -10dBm(540MHz)?
TX VCO ≥ -10dBm
(902MHz)?
Yes
No
U202 pin 5
No
voltage ≥ 3V rms?
Yes
U202 pin 4
No
≥ 2.0Vp_p(AC)?
Yes
No
No
No
Resolder C147, C146, R135, R133,
No
R134, R132, R131, C142, C138, C139,
R504, C165, C927, R121, R120, R123,
C130 or replace if damaged.
Check R208,R209,R210, C943,
F201 or replace if damaged.
F201 Resolder or Change F201
No ResolderC208, U202 or
replace if damaged.
Resolder U202 or
replace if damaged.
Resolder R215, C213, R212, C214,
No
R213, C210, U206, U205,
U202,U203 or replace if damaged.
Resolder FB100, U202, U204
or replace if damaged.
U202, U204, U205, C225 Resolder
or change poor component(s)
R139, C174, U204, U109
Resolder or Change U204, U109
C223, U204 J410 pin 21 Resolder
Samsung Electronics