Tuner Malfunction(Fm/Am) - Samsung MAX-810 Service Manual

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

IZD1(8.2V) Voltage ok ?
Check TUNER IC(LA1836)
pin no.10 ; 8.2V
pin no.14 ; 7.2V
AM ; 0V ?
FM VT
LC72131 pin no.20
1.7V
AM VT
LC72131 pin 20
0.9V
Check HIC1
pin 20 ?
LPF1,2
output ok?
Samsung Electronics
No
Yes
No
Yes
No
7.5V ?
Yes
No
7V ?
Yes
No
Yes
Yes
RIC1(BA3950) Voltage ok?
PIN NO.8 : 12V
Check the voltage ok ?
HZD1 (5.6V) Voltage ok?
HIC1 (LC72131) FM/AM BAND
Switching ok?
LC72131
CONTROL ok?
Check the LC72131
CONTROL ok?
Check BIC1 TDA7439 function ok?
No
Power section defective
1) Power impaired
No
so repair defects.
2) LC72131 Oscillator
(HX1 : 7.2MHz) ok ?
3) System line ok?
Yes
Check for µ-com IC
No
Replace LC72131
No
Check FEP interior
No
pattern, and any line
disconnections.
Troubleshooting
No
6-3