70
28. Grand Wega Video Process
Conclusion / Troubleshooting
What does all this mean? How can we use this video path switching to determine which board contains the video
problem? Refer to the flowchart in Figure 28-5 to determine if the problem is in the A, U, BC, BC4, BB board or
the optical unit optical assembly just by noting where the video problem moves as you increase the picture size
in the Twin View Mode.
Does the NTSC
picture have a
picture defect?
Does the problem
appear in all inputs
(video / component)?
If the problem is
in the Tuner and
video 1-4, change
the U board.
If the problem is in
component video,
change the BC board.
Press the "Twin Mode"
button on the remote
control and make the
RIGHT picture larger.
Does the problem remian
where it is on the screen?
Do both pictures have
the same problem?
Make the LEFT picture
larger. Where is the
defect?
BC and BC4 boards are both
suspect. Unplug the BC4 board
and jump the A board's
CN1901/pin 1 to pins 3 and 5.
Problem gone?
If the video problem is
stationary, the optical unit
optical assembly is
defective. Replace it.
Change the
BB board.
(MID circuit problem).
Change the
BB board.
(DRC circuit problem).
Change BC4 board.
Change BC board.
No. Moves to a picture
No
Different
Pix
Yes
Yes
Same
Pix
Yes
No
FIGURE 28-5 - FLOW CHART
ISOLATING THE VIDEO PROBLEM USING THE TWIN
PICTURE MODE
4/16/02
No
Yes
