Receiver Section - Samsung SCH-3500 series Service Manual

Trouble Shooting

8-2 Receiver Section

8-2-1 AMPS mode
Start AMPS mode.
Check
NO
AMPS 12dB SINAD
OK?
YES
Check LNA
in/output OK?
(Gain: +20dB)
YES
Check MIXER
in/output OK?
(Gain(AMPS): +10dB)
YES
Check IF Filter
in/output OK?
(Loss: -5dB)
YES
RSSI OK?
YES
(When RX Input Level is
RSSI displays 40-60 in test mode 01,090363,75)
RF RX AMPS OK.
(IFR input: -30dBm)
SAMSUNG Proprietary-Contents may change without notice
NO
Check Duplexer
& LNA power.
YES
NO Check 1st
local & mixer power
OK?
(Local:0dBm)
NO
Check IF Filter
soldering.
YES
NO
Check 2nd
local OK?
-90 dBm,
8-7
NO
Check PLL(U204)
& VCO output.
(VCO output: -6dBm)
NO
Check PLL(U204)
& IFR #25.