Sony TV-700U getting audio but no video

[matthewray2b]

I have an adapter running from the EXT ANT port to my Magnavox Odyssey 2. Changing to channel 3 and turning on the Odyssey gives me sound but no video. I can hear the Odyssey beeping from the TV and can hear the game playing but all I get from the video is static. The static pattern changes when I turn on the system but it does not looking like the game. Also, the Odyssey works fine on other TVs. Any ideas?

[old_tv_nut]

Have you tried tuning to channel 2 or 4 to see if maybe the fine tuning is far off?

[matthewray2b]

Originally Posted by old_tv_nut

Have you tried tuning to channel 2 or 4 to see if maybe the fine tuning is far off?

Gave that a shot and I got some video but it went away after a little bit. What does that mean?

[old_tv_nut]

Describe it more - did the screen go black, did the picture disappear suddenly or gradually. Did it look normal or strange in some way? Did you try the fine tuning?

[matthewray2b]

It kind of works on another channel. I've tried adjusting the knobs on the rear and side and have been able to put together a much nicer picture, but it's still pretty warped and wobbly. The rear has "H. Freq", "V.Lin", and "Height". I'm not sure what any of these mean though. I know that H. Freq means Horizontal Frequency but I'm lost what V. Lin means and what Height does (changes the height?). The side has vertical and horizontal. I'm assuming they just change the location of the image on the screen, but they seem to change something on the image. It would be nice if I knew what all these knobs meant so I could get the image right.

[old_tv_nut]

The side controls are the customer controls. If the set is working properly, they are all that are needed to lock in the picture from rolling up or down (Vertical Hold) and the H is similar for horizontal except that the effect will be that the picture tears into diagonal stripes if it is misadjusted.

Adjusting the controls on the back should only be necessary if the set needs some servicing.

Height does just what you think - shrinks or expands the height of the picture.
Vertical linearity adjusts the picture so top and bottom have the same amount of stretch or shrink. If misadjusted, the picture will look a bit like a fun house mirror.
It is OK to play with these vertical controls to see the effect, as it will be easy to reset them.

I'm not familiar with this set, so don't know why there's a Horizontal Frequency control accessible, but essentially it should set the center point for the H contol on the side. This one could cause you more trouble if you play with it and get lost from the correct setting.
It probably should not be touched unless the side H control cannot make the picture lock horizontally. If that's the case, center the side H control, then adjust Horizontal Frequency for lock. Take careful note of how much you turn it so you can go back if your adjustment doesn't work. It will probably be touchy and have a strong effect, such that good adjustment will occur over only a small range of rotation. Double check that the side H control locks the picture when centered and unlocks it about equally bad when full CW or CCW.

[Alex KL-1]

I have one TV-700U working.

Besides that tv-nut said, I can add in practice, fortunately this set are not overly fussy about the V and H user controls (in the side), but anyway, for game console having a little different freq. for H, V or both, a simple readjustment makes the day.

But, maybe it have some sound or video IF misaligment; perhaps marginal to other sources, but maybe being far off for the Magnavbox. If is impossible to find a usable point using the fine tuning, perhaps this are ocurring.

BTW: my set needed a "full cap service", ie, all electros are bad. This can even influence the sync separator, since electro are involved for biasing and coupling. This makes the set fussy about the sync.

In my to-do list is some realigment for my TV-700U; the sound is a little off.

[zeno]

One caution. The service adjustments ( h-freq, V-lin, V-size ) are
very small & delicate. They also have lock tight on them often.
SO go very easy on them !
Sounds like the electrolytic caps are bad in both the Hoz & Vert.
It could also be just a dirty tuner.
BTW the fine tune is multy turn. Could be that is way off.
When you see the pix try turning it 1-2 turns CW & see what happens.
Sometimes you also need to push it in too to engage the gears.

73 Zeno
LFOD !

[matthewray2b]

May have made the mistake of fiddling with the knobs too much to begin with so I'm kind of starting with a clean slate. The Horizontal and Vertical knobs both mess with the wobbliness of the screen (the alignment?). I can get the screen almost centered then it just goes out of wack. I turned both of the knobs so that they're at the center location because that seems like roughly where the center point is. I go to adjust the horizontal frequency and I can almost get it just right but not quite.
The best I can get is the screen being slanted. I've adjusted it multiple times and the slant is always in the same direction too.

Here's a video of my fiddling with stuff so you guys can see what I'm talking about. I don't know if it's all a problem with the TV or some stuff needs to be replaced. The knobs are unbelievably sensitive to touch. Sometimes just removing the screwdriver that I am using to turn them is enough to make the image more messed up.

https://www.youtube.com/watch?v=0924Aq3syXc

[old_tv_nut]

Your horizontal and vertical are working just fine. However, the image with the edges affected like that would indicate that the fine tuning is way off, to the point that you may be on the wrong channel. It could also be that there is a problem with IF (intermediate frequency section) alignment, but that is MUCH less likely.

If your source is supposed to be channel 3, go to channel 3 on the receiver and then try turning the fine tuning as far as it will go one way and then the other to see if you can find a good picture that locks in solidly.

[matthewray2b]

I tested all the other channels and the current one worked the best still. I think I am going to reapply deoxit cuz I may have not done a good job the first time. I may also try using a different device for the input just for diagnostics' sake. Any other ideas? What's the "intermediate frequency section"?

[matthewray2b]

Originally Posted by Alex KL-1

I have one TV-700U working.

Besides that tv-nut said, I can add in practice, fortunately this set are not overly fussy about the V and H user controls (in the side), but anyway, for game console having a little different freq. for H, V or both, a simple readjustment makes the day.

But, maybe it have some sound or video IF misaligment; perhaps marginal to other sources, but maybe being far off for the Magnavbox. If is impossible to find a usable point using the fine tuning, perhaps this are ocurring.

BTW: my set needed a "full cap service", ie, all electros are bad. This can even influence the sync separator, since electro are involved for biasing and coupling. This makes the set fussy about the sync.

In my to-do list is some realigment for my TV-700U; the sound is a little off.

How could you tell it needed new caps? Were they just visibly bad?

[jr_tech]

Originally Posted by matthewray2b

I tested all the other channels and the current one worked the best still.

On the best channel, does the picture change when you adjust the fine tuning control? If not, the control is possibly not engaging.

jr

[matthewray2b]

Originally Posted by jr_tech

On the best channel, does the picture change when you adjust the fine tuning control? If not, the control is possibly not engaging.

jr

If by "fine tuning" you mean the Horizontal Frequency knob then yes, it is engaging. You can see it working in the video.

[jr_tech]

No, I mean the fine tuning knob...the outer ring around the channel selector knob. Push to engage.

jr