Samsung SGH 600, Service Manual

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5-2 Samsung Electronics
Troubleshooting
5-1-2 TX Power Problem
CH.60 (902 MHz) &
Tx Carrier ON (Power level 5)
F201 Input
≥
- 10 dBm?
RF VCO
≥
-10dBm(1172MHz)?
IF VCO
≥
-10dBm(540MHz)?
TX VCO
≥
-10dBm
(902MHz)?
U202 pin 4
≥
2.0Vp_p(AC)?
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
F201 Resolder or Change F201
ResolderC208, U202 or
replace if damaged.
Resolder R215, C213, R212, C214,
R213, C210, U206, U205,
U202,U203 or replace if damaged.
Resolder FB100, U202, U204
or replace if damaged.
Resolder C147, C146, R135, R133,
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 Output
≥
-15 dBm?
U202 Input
≥
- 15 dBm?
U202 Output
≥
30 dBm?
U204 Input
≥
30 dBm?
U204 Output
≥
30 dBm?
I/F Connector pin 21
≥
30 dBm?
Yes
Yes
Yes
No
No
No
Yes
No
Yes Yes
No
Yes
No
Yes
No
No
No
U202 pin 5
voltage
≥
3V rms?
Resolder U202 or
replace if damaged.
Yes
No