Tuner Malfunction (Fm/Am) - Samsung MAX-460V Service Manual

6-1-3 Tuner Malfunction (FM/AM)

IZD1(8.2V) Voltage ok ?
Yes
Check TUNER IC(LA1836)
pin no.10 ; 8.2V
pin no.14 ; 7.2V
AM ; 0V ?
Yes
FM VT
LC72131 pin no.20
1.7V 7.5V ?
Yes
AM VT
LC72131 pin 20
0.9V 7V ?
Yes
Check HIC1
pin 20 ?
Yes
LPF1,2
output ok?
Samsung Electronics
No
RIC1(BA3950) Voltage ok?
PIN NO.8 : 12V
Check the voltage ok ?
No HZD1 (5.6V) Voltage ok?
HIC1 (LC72131) FM/AM BAND
Switching ok?
LC72131
No
CONTROL ok?
No
Check the LC72131
CONTROL ok?
No
Yes
Check TDA7318 function ok?
No
Power section defective
1) Power impaired
No
so repair defects.
2) LC72131 Oscillator
(HX1 : 7.2MHz) ok ?
3) System line ok?
Check for µ-com IC
No
Replace LC72131
No
Check FEP interior
No
pattern, and any line
disconnections.
Troubleshooting
No
Yes
6-3