I have been enjoying my new Magnavox 21" B&W,
thanks to everyones help here.

A new black line, with some white dashes just appeared at the top of the screen when I am watching DVD's.
Tried the Vertical Hold at the top of the set,
and right before it dissapears, the vertical goes out of sync.
I tried adjusting the vertical height at the bottom of the set,
and I can get rid of it, but then a white glare comes up from the bottom!
Any ideas?
Thanks!

Magnavox300

only dvd's, how is cable tv on this set?

only dvd's, how is cable tv on this set?

Only DVD's.
I actually gave up regular TV years ago.

The height interacts with vertical linearity control, did you try adjusting both? You might also measure the line voltage where the TV is plugged in. If it sags, the picture will shrink. Usually shrinkage at the sides becomes evident first, but it would be good to confirm it's at least 115.

Try the centering rings on the back of the yoke. Should be able to nudge the whole raster up a bit.

You're seeing the very top of the raster, which also means you're seeing a part of the picture that's normally out of view. As I understand it, the first few lines of the video signal were repurposed to add text or other info. It shows up as dancing white lines. To get rid of it, you need to play with vertical height, centering and linearity. First center the raster in the middle of the screen, then use the height pot to overscan the CRT face slightly. Lastly, adjust the linearity pot so the raster is uniform top to bottom. This is best done with a crosshatch pattern on the screen, but you can eyeball it with off air images.

Thanks!
It is almost perfect, centering rings got rid of most of it,
now I will adjust the vertical linear and height to make it just right.
Thanks to everyone for all the expert information!

Magnavox300

let it warm up at least 15 min before making any adjustments.

It's the analog closed-captioning data, on line 21 of the vertical interval. Normally blanked, of course... Line 21 is sposed' to be the last unseen line before active picture.

Chip

If you were viewing broadcast TV and saw these lines, dots, etc. at the top of the picture they would be what are known as Vertical Interval Test Signals (VITS). These show in the vertical blanking interval and are (or were) used to adjust such things as video levels and so forth. These signals, when seen in the blanking interval of non-broadcast images such as those from DVDs, however, are, as has been noted, for text, closed captioning, and other advanced functions of today's TVs. Some GE televisions of the '70s had a feature known as "VIR", which was supposed to automatically control hue, brightness, saturation, etc. of a color picture according to a signal sent by the broadcaster in the vertical blanking interval. I do not know if the VIR signal was ever visible in the blanking bar, in addition to network VITS or otherwise.

VITS are still used in broadcast TV today, but are normally invisible to viewers since the blanking bar is ordinarily off the top of the screen on properly scanned TVs, as were the older versions of these signals. The signals are likely used for closed captioning, text, etc. as they are for DVDs and other non-broadcast applications.

The "white glare" at the bottom of your TV picture when you are trying to adjust vertical height and linearity is called foldover. It occurs when these controls are incorrectly set (normally far too high) such that the lower part of the image on the television screen is actually, literally, folded over onto itself. The cure is to adjust the height/linearity controls so the picture just overscans the CRT mask at top and bottom. Since these controls normally interact with each other, you may need to fiddle with the adjustments (trial and error) until you get the desired result.

VITS are still used in broadcast TV today...

Alas. VITS is no longer broadcast. Analog TV broadcast included the vertical blanking interval to carry data such as VITS, Closed captions, Nielsen data etc. But DTV does not accommodate carriage of the VBI or vertical blanking interval. Only the active picture is broadcast with the ancilliary data carried as separate data packets ins the digital broadcast stream.

DTV receiver boxes and DVD players recreate VBI signals from the ancillary data. This is to provide a backward compatibility with older analog TV.

So we can now say V.I.T.S. - R.I.P.

Alas. VITS is no longer broadcast. Analog TV broadcast included the vertical blanking interval to carry data such as VITS, Closed captions, Nielsen data etc. But DTV does not accommodate carriage of the VBI or vertical blanking interval. Only the active picture is broadcast with the ancilliary data carried as separate data packets ins the digital broadcast stream.

DTV receiver boxes and DVD players recreate VBI signals from the ancillary data. This is to provide a backward compatibility with older analog TV.

So we can now say V.I.T.S. - R.I.P.

I guess I have a lot to learn about digital TV. I was not aware of the fact that there are no VITS in broadcast DTV signals, although common sense tells us that since there is no vertical blanking bar in a DTV picture, and since DTV is completely different from NTSC analog, there is no need for VITS (at least as we used to know them in the analog NTSC era) any longer.

I also did not know that the data once carried by VITS in analog NTSC broadcasts are now contained in data packets nestled in the DTV stream itself.

Boy, how things have changed for TV since the DTV transition. No more VITS, no vertical/horizontal sync problems, no more worrying about convergence adjustments, the sets themselves are much smaller and slimmer than their NTSC counterparts, the pictures are much better in 16:9 ATSC digital than those in the old NTSC 4:3 standard . . . it's all new and different for people like myself who grew up with NTSC analog.

The backward compatibility with older NTSC analog TVs may be done away with sooner than we think, as more and more people replace their NTSC analog sets with digital flat screens. NTSC analog TV, after all, is no longer broadcast in the U. S. and now Canada, so the older TVs built for the NTSC standard are now obsolete. Some people, such as VK's own Doug Harland, drh4683 (where on earth is he hiding?), may continue to use older NTSC sets with converter boxes and antennas, but he is a collector, so he is going to want to keep his old sets going as long as possible.

For almost everyone else, however, once the old NTSC TV finally shows its last program and dies of a serious problem, it will be trashed ASAP and replaced with a flat screen. Remember also that most TV shops won't touch any television that is more than about five years old, and then only for warranty repairs on flat screens.

Tube-type or even solid-state NTSC TVs? Forget it. Many if not most of today's TV technicians (except those members of VK who work for TV shops, of course) don't know the first thing about working on very old TVs with picture tubes (CRTs) and vacuum tubes, so they would be stopped dead in their tracks, figuratively speaking, if one of these ever showed up in a 21st-century TV shop for service or repairs. I recall an old cartoon in a 1960s edition of, IIRC, the now long defunct Electronic Experimenter magazine. The cartoon showed two TV techs looking at a tube-powered TV that has just come into their shop for repair. One tech took the back off the set, saw the vacuum tubes in the chassis, and then, a bewildered look on his face, turned to the other tech and asked, "What the hell is a vacuum tube?"

Had a 1977 Mot Ward with VIR only a 19 inch and $400 back then..

The last tv repair shop here in town closed months ago.. Not goood....

I seem to recall a cartoon in the local paper here years ago with a pic of a repair shop and a tv with a hand holding a screwdriver punched through the face of the CRT from the back with a one worded caption "DAMN!"

It looks like the height is too short to me, if you can't easily adjust it out try a new Vert Output tube.