Problem with "Underscan" on Philips WSTV (1 Viewer)

[PhilipG]

Lately my Philip WS/32" telly has developed a very slight red line at the top of the screen, as if there isn't enough overscan to push it out of view. This red line disappears when I hit the on-screen menu button... but that's not the ideal way to watch my DVDs...
Can anyone please help? The tilt function does not help (it only shifts either the left or the right part of the red line off-screen, and thickens the other side.

 

[Allan Jayne]

It is possible that the DVD player is generating that red line and you never saw it before because the TV had more overscan. If so the only way to get it off the screen now is to increase the vertical size or position to push it off.
As TV sets age, different parameters may change including the overall shrinking of the picture. If your set has reached the point where there isn't enough range left in the vertical size to expand it again, you are out of luck.
Some sets have both service menu and regular menu settings, or both pots in the back and regular menu settings for picture size. If yours does, try adjusting both to see if you can enlarge the picture enough.
Other video hints:http://members.aol.com/ajaynejr/video.htm

 

[PhilipG]

Thanks a lot for your reply. My TV's just over a year old, and besides the red line (which only actually appears for NTSC material...hmmm), it's functioning great.
The problem now then is to find out how to activate my service menu... The standard menus just do contrast, colour etc.

 

[Seth Paxton]

Well, often there is data, test signals, etc on the lines just before scan info. I think AKB signal lines of Red, Green, and Blue can sometimes be there on the lines right before video kicks in (17-20 or somewhere in there).
It sort of sounds like it to me.
I'll give you an example that is similar. You have Closed Captioning data coming in on line 21. You have picture beginning at line 22.5. You adjust the height on a 4x3 to do the squeeze. Well, now you are scanning the other lines onto the tube as well. Mostly harmless, but you will now see the flickering white lines/dots of 1's and 0's that are on line 21 carrying closed captioning data. The CRT just scans the signal on the line if it's there, even if its not a picture signal.
Maybe your TV needs an adjustment if it is scanning overscan info onto the tube. Sounds like a deflection setting should be adjusted to get the overscan area back above the viewing area.
Just a guess though, not solid info.

 

[PhilipG]

It's a weird problem all right. The red line can be completely hidden, and then, for example while watching a movie, and the screen fades out, the red line appears, then when there's a picture again, the red line hides itself again. This is particularly noticeable while watching single-line credits at the end of a movie.
I wonder if it's possible that my centre speaker (placed below the TV) contributes to the red line at all? There is no direct relationship beween loudness and the red line that I can tell, but it might still be a factor

.
My TV is also positioned differently now - since I moved home, I'm 99.9% sure it's not facing the same way it was. I think I read somewhere that N-E-S-W alignment can affect picture tilt to a degree...
Anyway, whatever the cause of the problem, I shall still need to find out how to get to the elusive service mode menu.

Thanks a lot for your reply though Seth.

 

[Allan Jayne]

If the red line comes back when the picture fades to black, chances are it is simply due to the entire picture expanding slightly when the average content gets lighter. This is quite common, the better the set, the lesser the degree of this expansion. Overscan was invented partly to hide this effect, manufacturers just used more overscan so black borders did not come into view.

 

[PhilipG]

Interesting, Allan, that would explain it then - and also why it appears more often when watching films in the scope aspect ratio. I guess that increasing the brightness on my TV may alleviate the problem (something I am loathe to do!).