SAMSUNG max870, max878 Troubleshooting
Front PCB µ-com VDD(5V)
normal?
UIC1 pin no. 18,46,90
Check the Main PCB
RIC2(MC7805),FJ1
Check the Front PCB
UD9(1N4002), CN1-1
Main PCB RIC2(MC7805) IN: 12V
Input voltage normal?
Yes
Check the Main PCB;
RIC5(MC7812),PBD2
RR11 10Ω(1/2W)
Check the Power PCB;
Fuse P/T, PW1
Yes
No
No
Front PCB
Does UX1(6MHz)
oscillate ?
FRONT PCB PWR-SENS
voltage normal ?
(pin no. 11 ; 5V)
Check the Main PCB
RD4,RR19,RC13,RZD3
RC12,RR22,RR20
Yes
Front PCB
When the power is
ON 'H' displays
at pin no. 3 ?(5V)
Yes
Check the Main PCB
RQ7(C1008Y),RR9(22K)
RQ6(B1566), RR8(680Ω)
Replace µ-com.
Yes
No
No
No
Samsung Electronics 6-1
6. Troubleshooting
6-1 Amplifier
6-1-1 Power Malfunction
6-1-2 No Output
Yes
AQ8L, 8R, 1L, 1R ?
Is Mute selected ?
Remove it with Remocon.
Main PCB AIC1
pin no. 1,8,16,17
B+,B- normal?
Check the B+,B- Power source
BPD1, RC7, RC8, RWA1
Check the Power PCB
Fuse, P/T, PW1
Yes
Check the Main PCB
AIC1, FIC2, FIC1
No
No
Yes
Check the Main PCB
AQ8L,8R,1L,1R
No
Headphone Jack short ?
Check Headphone jack
soldering condition.
Yes
No
UIC1(µ-COM) pin 5
Check the Front PCB
UIC1 (µ-COM).
Yes
No
Check the "H"?
Base B+?
6-2 Samsung Electronics
Troubleshooting
Loading...