Samsung MM-26 - Tuner Malfunction (FM;AM)

Samsung Electronics 6-3
Troubleshooting
6-1-3 Tuner Malfunction (FM/AM)
IZD1 Voltage ok ?
Yes
Check TUNER IC(LA1836)
pin no.10 ; 7.6V
pin no.14 ; 6.5V
AM ; 0V ?
HZD1 (5.6V) Voltage ok?
HIC1 (LC72131) FM/AM BAND
Switching ok?
No
Yes
LC72131
CONTROL ok?
Yes
FM VT
LC72131 pin no.20
1.7V 7.5V ?
Yes
AM VT
LC72131 pin 20
Check the LC72131
CONTROL ok ?
Yes
Yes
Check HIC1
pin 20 ?
LPF(IL1, IL2)
output ok?
Check LC75394E function ok?
Check FEP interior
pattern, and any line
disconnections.
1) Power settion
defective ?
2) LC72131 Oscillator
(HX1 : 7.2MHz) ok ?
3) System line ok?
No
Yes
Check for µ-com IC
Replace LC72131
No
No
No
No
No
No
No
Yes
0.9V 7V
?
Check IZD1 (6.8V), IR6