Text preview for : samsung dsb-b350w.pdf part of Samsung samsung dsb-b350w Samsung Sat DSB-B350W samsung dsb-b350w.pdf
Back to : samsung dsb-b350w.pdf | Home
5. Troubleshooting
NO POWER (LED OFF)
Power switch and No
power plug pin is Connect switch and power plug pin.
connected?
Yes
SMPS OK?
check output voltage No
Check SMPS.
(3.3V,5V,12V,BT,17V,
24V)
Yes
No
Front PCB ass'y is OK? Check fr ont PCB ass'y.
Yes
U1 (12, 13) signal? No
Check X1
: 27MHz CLK
Yes
U1 (2) signal? No
Check U1
: 27MHz CLK
Yes
120MHz CLK is No
Check R26
occurred at R26
Yes
Check U2
Samsung Electronics 5-1
Troubleshooting
NO LOCKING
U901(40,14) No
Voltage 3.3V? Check SMPS 3.3V
C918:2.5V?
Yes
No Check U12(2) No
U902 input voltage Check SMPS 5V.
C926: 5V? 5V output?
Yes Yes
U9 LNB Voltage No No
HOR: 17~19V Check U9(1,2) Check SMPS
VER:12.5~14V input voltage 17V, 24V.
Yes
Check 12C of U901 No
(21, 22) is h high? Check U901.
Yes
CHU307 Data, control No CIIC1(40~50,53~63) No
Check U2.
appear at RP12,RP13 data control signal
RP14? is OK?
Yes Yes
Check U901 Check CIIC1.
5-2 Samsung Electronics
Troubleshooting
NO RF-MOD OUTPUT
Q4 base is high? No
Check U2.
(3.3V)
Yes
No
Q3 collector is 5V Check Q3.
Yes
C82 No
is 30