BBK DV718SI - Page 43

Video has no output
Check
whether output
mode switch is
correct
Restore setup mode
2. Troubleshooting process for “Video has no output” is shown in the figure 3.2.2.2:
N
Check
whether 27M clock is
normal
Restore setup mode
N
Y
Check
whether power
supply of MT1389 video
output part is
normal
N
Y
Change MT1389
Whether
component video has
output
Check component video
output circuit
N
Y
Whether
composite video has
signal output
Change MT1389
N
Y
Y
Whether
pin 187 of MT1389
has signal
output
N
Y
OK
Check video filtering circuit
Check
whether JK703 has
signal output
N
Y
Change JK703
Figure 3.2.2.2 Troubleshooting flow chart for “Video has no output”
- 39 -