DSP has no output
Switch
digital input or
analog input and check
whether there is
no output
Digital signal has output
N
Analog signal has output
Check
w5V,
+3.3V and 2.5V of decode
board power supply voltage
is normal
Y
Y
Check
whether pin 10,
12 of decode board
N108 has
signal
Y
N
N
Test
whether R128
and R131 have
waveform
Check
whether signal
board C108 and C107
have waveform
Change signal board N111
Input
optical signal
and test whether decode
board L119 has
signal
Y
Test
whether decode
board L121 voltage is
normal
Test
whether decode
board C207 has
signal
Y
Change C207
Change N101
Y
Test
whether decode
board L101 voltage is
normal
Refer to troubleshooting
process for voltage
Y
Change N106
Check
whether N108
power supply is normal,
whether RST is
normal
Change N108
Whether
N111 power supply is
normal
Change N111
Check flat cable XP17
Check
whether voltage
of decode board L102 is
normal
Refer to troubleshooting
process for voltage
Change decode board N106
N
Test
whether N105
power supply is
normal
Change N105
Change N107
Refer to troubleshooting
process for voltage
Y
Y
Y
Y
N
Y
N
N
Disconnect
decode board resistor
R155, test whether two ends
of resistor R155 have
waveform signal
(MCLK)
Input
sine wave to
VCD channel, under DSP
decode state, test whether
waveform of pin 39, 40, 41, 42, 43
of N105 is
correct
Y
Test
whether waveform
of pin 19, 20,23, 24, 26, 27
of N107 is correct (refer to
key point
waveform)
Y
Y
Check decode board
N106, C107, C108
N
Y
Y
N
N
N
Y
N
N
