SAMSUNG Ncp-50fh, Ncp-70qh, Ncp-10qh Troubleshooting
8. Troubleshooting
8-1 Power Malfunction
Main PCB µ-com VDD(5V)
normal?
UIC1 pin no. 18,47,90
Top PCB ARIC1(K7805) IN: 10V
Input voltage normal?
Main PCB PWR-SENS
voltage normal ?
(pin no. 27;5V)
Main PCB
Does UX1(6MHz)
oscillate?
Main PCB
When the power is
ON 'H' displays
at pin no. 5 ?(5V)
Replace ARIC1
Check the Power PCB ;
ARD 1, 2, 3, 4 (IN5392)
AF2 (1.25A Fuse)
Connect Top PCB and Main PCB.
Check the connector Main PCB.
Wafer ucw3
No No
Check the Main PCB
ARZD1, ARR 7, ARR6
ARD5, ARC5, 12
No
No
No
No
Yes
Yes
Yes
Yes
Replace µ-com.
Check the Power PCB : P/T, FUSE
Yes
Samsung Electronics 8-1
Samsung Electronics
Troubleshooting
8-2
8-2 No Output
Main PCB AIC1
pin no. 9,4,12,8
B+,B- circuits
AQ 7,8 Base B+ ?
Is Mute selected ?
Check the B+ power PCB
AD1,2,3,4, AF1,3
Confirm for TR short
replace it.
Remove it with Remocon.
Replace Headphone jack
soldering condition.
No
No
No
No
Check if the output line is
short.
Yes
Yes
Yes
Yes
Headphone Jack short ?
Samsung Electronics
Troubleshooting
8-3
8-3 Tuner Malfunction (FM/AM)
TZD2(8.2V) Voltage ok ?
Check TUNER IC(LA1836)
pin on. 10 ; 8.2V
pin on. 14 ; 7.2V
AM ; 0V ?
FM VT
LC72131 pin no.20
1.7V 7.5V
Power section defective
Check for µ-com IC
Replace LC72131
Check FEP interior
pattern, and any line
disconnections.
No
No
No
No
No
No No
Yes
No
No
Yes No
No
Yes
Yes
Yes
Yes
Check MIC6
pin 20 ?
LPF1,2
output ok ?
Yes
AM VT
LC72131 pin 20
0.9V 7V ?
AQI(C4369) Voltage ok ?
PIN NO.8 : 12V
Check the voltage ok ?
TZD3(5.6V) Voltage ok ?
MIC7(LC72131) FM/AM BAND
Switching ok ?
1) Power impaired
so repair defects.
2) LC72131 Oscillator
(HX1 : 7.2MHz) ok ?
3) System line ok ?
LC72131
CONTROL ok ?
Check the LC72131
CONTROL ok ?
Check(TDA7449) function ok ?
QIC1
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