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  #16  
Old 11-18-2018, 05:46 PM
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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.


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  #17  
Old 11-18-2018, 06:02 PM
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Quote:
Originally Posted by Eric H View Post
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.
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Last edited by Jeff-20; 11-18-2018 at 06:18 PM.
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  #18  
Old 11-18-2018, 06:39 PM
zeno zeno is offline
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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 !
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  #19  
Old 11-19-2018, 12:58 AM
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Quote:
Originally Posted by zeno View Post
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...
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  #20  
Old 11-19-2018, 09:25 AM
kf4rca kf4rca is offline
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Could be the set was connected to an outdoor antenna during a lightning storm and the 1st RF amp transistor got blasted.
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  #21  
Old 11-24-2018, 12:25 AM
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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?
Attached Images
File Type: jpg IMG_7356.jpg (49.2 KB, 30 views)
File Type: jpg IMG_7354.jpg (73.0 KB, 36 views)
File Type: jpg IMG_7359.jpg (61.3 KB, 38 views)
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  #22  
Old 11-24-2018, 07:23 AM
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Quote:
Originally Posted by Jeff-20 View Post
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?
No surprise there, most sets I've opened have the RF input cable soldered in place. In my experience those things need really good grounds. If the 1st RF amp transistor is blown it'll be a real dog to replace if even possible, it's pretty tight in there. Unless you have a schematic that identifies the transistors don't bother trying. Any tuner that uses approximately the same B+ voltage should work even if it doesn't physically fit. Fortunately for me a blown tuner was very much the same internally as one from my parts stash, the most important feature being a removable shaft. The hardest part will be swapping the front of the housing so it will mount properly.

The damage to the CRT anchoring point has nothing to do with the image size issue.
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  #23  
Old 11-24-2018, 09:31 AM
zeno zeno is offline
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Cabinet damage means the set took a good lickin. Thats why I said
to give the main PCB a look for cracks. Especially at the mounting
lugs & the flyback.

73 Zeno
LFOD !
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  #24  
Old 11-24-2018, 11:36 AM
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Quote:
Originally Posted by Jon A. View Post
No surprise there, most sets I've opened have the RF input cable soldered in place. In my experience those things need really good grounds. If the 1st RF amp transistor is blown it'll be a real dog to replace if even possible, it's pretty tight in there. Unless you have a schematic that identifies the transistors don't bother trying. Any tuner that uses approximately the same B+ voltage should work even if it doesn't physically fit. Fortunately for me a blown tuner was very much the same internally as one from my parts stash, the most important feature being a removable shaft. The hardest part will be swapping the front of the housing so it will mount properly.

The damage to the CRT anchoring point has nothing to do with the image size issue.
His problem is probably a dirty tuner (easy fix) versus your transistor issue (not particularly easy).

First step on any noisy tuner issue should always be clean the contacts. You should not need to remove the whole tuner from the cabinet or any wires from the tuner. Most sets made it so that you could unclip and remove the tuner shield and clean the contacts with the tuner still mounted and connected. There is a front and back to the tuner that the shaft passes through and a "top" that the wires connect to(some tuners are mounted upside down or other wacky ways so "top" is not always pointing up)...The removable shield typically comprises the bottom and sides of the tuner. It usually clips into the top. To remove pinch the sides inwards near their centers at their upper edge where they meet the "top" and pull down after you've started to pinch while still pinching...The shield should slide off. After that identify the contacts and start spraying cleaner and spinning the knob...If there is lots of room around the contacts I like to stick a soft white pencil eraser in there and let the contacts brush against it...This alone will help but if you do it while they are wet with contact cleaner you will be impressed with how much tarnish it will remove.
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  #25  
Old 11-24-2018, 06:08 PM
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Quote:
Originally Posted by Electronic M View Post
His problem is probably a dirty tuner (easy fix) versus your transistor issue (not particularly easy).
I guessed that this reply would contain an argument against what I said. You've done it to me many times, please try to refrain from it from now on. I know I'm not stupid but it still kind of stings.

It may be true that his tuner is dirty, but it wasn't I who initially suggested that the RF amplifier transistor may be blown.
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  #26  
Old 11-24-2018, 06:38 PM
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Quote:
Originally Posted by Jon A. View Post
I guessed that this reply would contain an argument against what I said. You've done it to me many times, please try to refrain from it from now on. I know I'm not stupid but it still kind of stings.

It may be true that his tuner is dirty, but it wasn't I who initially suggested that the RF amplifier transistor may be blown.
Not trying to sting nor to imply any kind of stupidity. The topic has drifted away from what he needs to do into speculation into highly unlikely causes. Your Post seemed to suggest replacing that transistor was the way to go and that it is very difficult (and it was the most recent bit of talk on it). That will scare an amateur off of touching the tuner. I simply pointed things back in the right direction. (we should make sure the easy common issues have actually been dealt with before going off into the weeds should we not?)

If what I see as bad advice is given I will attempt to correct it (or improve the advice given) no matter who gives it, starts it, or contributes to it...If you happen to be caught up in the giving of bad advice that is not my fault. And you have no right to tell me where and how I can put my two cents in on an issue as long as I am abiding by the rules of VK. I will try to sound more respectful going forward...But bear in mind we ALL get correct by other VK'ers from time to time, and unless someone explicitly calls you a big dummy that is likely NOT even a tiny part of their goal in offering what they see as the correct information to those reading.
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  #27  
Old 11-25-2018, 08:19 AM
kf4rca kf4rca is offline
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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.
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  #28  
Old 11-25-2018, 10:06 AM
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Quote:
Originally Posted by Jeff-20 View Post
As always, I have to jiggle the tuner a bit to get a signal.
That's a sure sign the tuner is dirty. RCAs are one of the worst for developing dirty tuner contacts when they haven't been used regularly. Sometimes they get so dirty that it's impossible to get a clear picture. There are cleaning sprays, but they are usually a temporary fix. It's best to manually clean/polish the contacts with something slightly abrasive like a pencil eraser, followed by some spray to flush away the debris and then some light grease to lubricate and help prevent oxidation. Be careful not to bend or move any wires or coils inside the tuner since that will affect the alignment.

For the size problem, verify the correct B+ voltage compared to the service manual. It's probably running low since both width and height are affected. As others have said, check the boards for cracks, loose wires, and other visual problems first. Make sure the plug in boards are seated properly.
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  #29  
Old 11-26-2018, 05:05 PM
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Have you tried to hook it up to a DVD or VCR?
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  #30  
Old 11-27-2018, 12:37 AM
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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.
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