DC
Ͳ
DC CONVERTER CIRCUIT 1
CHECK if the 12V OUTPUT
from U100(R194,R195)
1.CHECK if the 24V
INPUT at U100 PIN2?
1,L112,L113is open circuit
2,C116,C139 short circuit
3,powerboard failure
FAILURE POINT
CHECK if the 1.1V OUTPUT
at U107 (L100)
CHECK if the 12V
INPUT at U107 PIN2
CHECK if the
5V(Tuner_Vcc)
OUTPUT at U102 PIN2
(R193)
CHECK if the 12V
INPUT at U102 PIN3
1 L103 is open circuit
2,C100,C108,C140 is short circuit
3,IC U100
4.Other 12V net
FAILURE POINT
1,L120 is open circuit
2,C121,C160 is short circuit
FAILURE POINT
1,L100 is open circuit
2,C101,C104,C159 is short circuit
3,IC U107
4.Other VCCK(1V1) net
FAILURE POINT
1,R112,R199 is open circuit
2,C110,C115 is short circuit
FAILURE POINT
1,C154 is short circuit
2,IC U102
3.Other TUNER_5V net
FAILURE POINT
Y
N
Y
N
N
N
Y
N
Y
