1976 RCA picture problem

[Eric H]

Loosen the yoke clamp and make sure it's pushed all the way up against the back of the tube. It looks okay but obviously the set took a hard hit if the tube was dislodged.

[Jeff-20]

Originally Posted by Eric H

Loosen the yoke clamp and make sure it's pushed all the way up against the back of the tube. It looks okay but obviously the set took a hard hit if the tube was dislodged.

Complete newbie with these things. I am assuming that is the metal clamp wrapped around the glass. Should I take any safety precautions? I'm not sure what pushing back means: away from the screen or toward the screen.

[zeno]

For the yoke.......
Loosen the clamp.
Push all the way forward against the "bell" of the CRT.
Get a picture on & be sure its not tilted.
If its tilted rotate yoke a little bit. Use a glove or just be careful of
the wires. It wont kill you but you can get a surprise !
Slowly tighten clamp until you can JUST not move it. Done

For tuner.......
Pull tuner assy.
Remove the tuner shield. It has catches on both sides & slides off. It
is U shaped.
You will see 4 or 5 wafers that the shaft go through.
Spray a little contact cleaner or WD40 on the wafer part that moves.
Spin channel knob about 4 rotations each way.
Try it, should be clean now.

Other stuff.....
One pix shows hoz way off. Odds are the horz hold control is also dirty.
Spray cleaner into the gap where the 3 wires / pins enter.
Adjust back & forth a bunch then adjust to get a pix.

enuf fer now. I need an ale

73 Zeno
LFOD !

[Jeff-20]

Originally Posted by zeno

For the yoke.......
Loosen the clamp.
Push all the way forward against the "bell" of the CRT.
Get a picture on & be sure its not tilted.
If its tilted rotate yoke a little bit. Use a glove or just be careful of
the wires. It wont kill you but you can get a surprise !
Slowly tighten clamp until you can JUST not move it. Done

For tuner.......
Pull tuner assy.
Remove the tuner shield. It has catches on both sides & slides off. It
is U shaped.
You will see 4 or 5 wafers that the shaft go through.
Spray a little contact cleaner or WD40 on the wafer part that moves.
Spin channel knob about 4 rotations each way.
Try it, should be clean now.

Other stuff.....
One pix shows hoz way off. Odds are the horz hold control is also dirty.
Spray cleaner into the gap where the 3 wires / pins enter.
Adjust back & forth a bunch then adjust to get a pix.

enuf fer now. I need an ale

73 Zeno
LFOD !

It's not getting better...

[kf4rca]

Could be the set was connected to an outdoor antenna during a lightning storm and the 1st RF amp transistor got blasted.

[Jeff-20]

Making progress... Got the yoke twisted back in place per zeno's instructions (Thank you!). But not yet brave enough to take the tuner apart. All of the wires are soldered.

I took some pictures of the inside and discovered one of the corners that anchored the screen in place was completely broken! It must have gotten pushed in during shipping. I took pics of one of the normal corners and the broken one after some efforts to put in back in place. Would this kind of damage seem connected to the small image?

[Eric H]

In this picture the screen is filled all the way out, except the right edge and that seems to be because the Horizontal hold is off and flopped to the left.

[kf4rca]

If it was a dirty tuner, usually you can wiggle the shaft and they snow will come and go. Since it obviously took a spill I'd look for a broken resistor, wire or other component, (on top of the tuner or elsewhere).
You should have determined the location of the point of impact. Is that close to the tuner?
Did you check voltages at the tuner?
Might even be an IF problem.

[TVTim]

Have you tried to hook it up to a DVD or VCR?

[Jeff-20]

Originally Posted by TVTim

Have you tried to hook it up to a DVD or VCR?

Yes. The last image I provided (of a football game) is from a digital converter box capable of playing video off a hard drive. Like the Atari, the image is just small.

[user181]

Originally Posted by Jeff-20

Yes. The last image I provided (of a football game) is from a digital converter box capable of playing video off a hard drive. Like the Atari, the image is just small.

Did you try using the crop/zoom function of your DTV box?

[Jeff-20]

Originally Posted by user181

Did you try using the crop/zoom function of your DTV box?

My DTV doesn't seem to have that feature. Neither would the old video game, of course. Are you saying I should ignore the problem and just adjust the video source?

[user181]

Originally Posted by Jeff-20

My DTV doesn't seem to have that feature. Neither would the old video game, of course. Are you saying I should ignore the problem and just adjust the video source?

Not saying to ignore anything, just to be sure you identify the actual cause so you're not barking up the wrong tree. You really need to find some video source that outputs 4:3 format and connect that to your set. Then, you can tell with more certainty if your set is not displaying the signal correctly.

It would be ideal if you have another 4:3 TV so that you can use process of elimination to determine what the culprit is.


Incidentally, what is the make & model of your DTV converter box?

[old_tv_nut]

For gosh sake, three pages and no one has said how to determine if the small picture is the TV or the source? Just turn up the brightness control, and the whole raster will get bright. If the sides, top and bottom are still pure black, it's the TV raster being too small. If light appears in the black areas, then the problem is the source.

[Jeff-20]

Thanks for your input, everyone. I took it to a skeptical repair shop for a diagnostic. He seemed more interested in getting the $20 fee, but we'll see if he has anything to say about the problem.

Originally Posted by user181

Not saying to ignore anything, just to be sure you identify the actual cause so you're not barking up the wrong tree. You really need to find some video source that outputs 4:3 format and connect that to your set. Then, you can tell with more certainty if your set is not displaying the signal correctly.

It would be ideal if you have another 4:3 TV so that you can use process of elimination to determine what the culprit is.


Incidentally, what is the make & model of your DTV converter box?

The game source is an Atari 2600. It's only capable of 4:3 ratio output. The maker of the digital convertor is Ematic. I assure you the source is not the problem.

Originally Posted by old_tv_nut

For gosh sake, three pages and no one has said how to determine if the small picture is the TV or the source? Just turn up the brightness control, and the whole raster will get bright. If the sides, top and bottom are still pure black, it's the TV raster being too small. If light appears in the black areas, then the problem is the source.

I have adjusted the brightness and other settings. The image is simply small. Even the static screen. See some of the early pictures. Do you have any recommendations for adjustments?