Hello all,
I had previously posted info on problem I have been having with my Sony XBR and received excellent suggestions. But I wanted to post some additional info in hopes of narrowing down where to search for the problem. I don't think I described the problem properly before.
The new info is as follows:
I previously described the problem as vertical light bands, but the bands are really horizontal and are the result of bands of scan lines of relatively wide spacing alternating with bands of not so wide spacing but still more than normal space between them. The bands of wide and less wide scan lines appear to be about an inch wide. So it looks like primarily the vertical scan is being affected by a periodical signal. But there may be some affect on horizontal also as the straight edge of an object will be somewhat jagged-sort of following the pattern of the vertical scan band problem.
The evenly spaced alternating bands of coarse and less coarse scan lines cover the entire screen.
They never occur when the TV is first turned on and only appear (if at all) after about 15 minutes of operation. Some times they won't appear for a few days then come back with a vengeance. It is not tuner related since they also appear with DVD S-video input.
When they do appear, they will disappear in a low intensity picture and reappear in a bright/intense picture-they are usually very noticeable and harsh in kid's cartoon shows that have bright vivid colors and much less so or not at all in standard movie situation. So there is a picture intensity threshold that triggers them.
If I turn the set off and then turn on after a short time, there will be no lines until the degaussing relay clicks off and the lines instantly reappear at that time.
Is this a power supply problem-noise on B+?
As before, any suggestions, particularly ones that may narrow my search will be greatly appreciated.
Thanks in advance,
Dan