Receiver Section - Samsung SCH-A105 Service Manual

Troubleshooting

6-3 Receiver Section

RX part
Check CDMA
SVC&ROAM?
Yes
No
Check LNA
in/output OK?
Gain: +18 dB
Yes
Check mixer
in/output OK?
Gain: -11 dB
Yes
Check IF AMP
in/output OK?
Gain: +19 dB
Yes
Check IF filter
in/output OK?
Loss: -10 dB
Yes
RF Rx FM OK
BBA INPUT: -52 dBm
SAMSUNG Proprietary-Contents may change without notice
No
Check Duplexer
& LNA power
Yes
Check 1st
local & mixer power
OK?
local: - 5 dBm
No
Check IF AMP
power OK?
No
Check IF filter
solderling
6-7
No
Check PLL (U407)
& VCO output
BUFFER OUTPUT: - 5 dBm