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  #61  
Old 03-22-2017, 02:46 PM
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There is no change in resistance on pin 2 of v13 when the horizontal size pot is turned . but the voltage tests do vary with the movement of the size and hold pots.

Last edited by timmy; 03-22-2017 at 02:52 PM.
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  #62  
Old 03-22-2017, 02:58 PM
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Are you measuring the resistance from pin 4 of M-5, like the note at the bottom of the table says?

jr
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  #63  
Old 03-22-2017, 03:07 PM
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Sure did
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  #64  
Old 03-22-2017, 03:49 PM
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C-75 could be shorted, but I doubt that the horizontal would work ok if it was... a real head-scratcher.

jr
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  #65  
Old 03-22-2017, 03:56 PM
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Quote:
Originally Posted by jr_tech View Post
C-75 could be shorted, but I doubt that the horizontal would work ok if it was... a real head-scratcher.

jr
That's a 900mmf that cap along with the other Micas were changed but each one I replaced I tried the set and after all of them were replaced I was left with the same problem. I checked the horiz afc and block trans and ohms are perfect. So I don't know what it is with pin 2 or if it even has to do with this odd problem.

Last edited by timmy; 03-22-2017 at 04:14 PM.
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  #66  
Old 03-22-2017, 04:50 PM
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Could the blocking trans have a primary to secondary or windings to frame short?
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  #67  
Old 03-22-2017, 05:06 PM
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These transformers are small round things dipped in wax and the one trans is on a tie strap and the other is in a can on top and I took that apart and that one has insulating paper wrapped around it. So I guess it's safe to say I don't think there is a winding short to ground unless the ground was leaking in from somewhere else , I don't even know where to start to look for a possible ground leak into the verticle, and There is no 60hz hum in the audio.
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  #68  
Old 03-23-2017, 11:00 AM
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Still didn't figure this out, but there is 2 10meg resistors at the 6sl7 that I checked and also tried others and didn't work was the same no different but the one 10meg that is across pin 4 and 6 if I put a 1 meg across the 10meg I get a picture and vert hold the linearity is off on top and the hold is Alittle touchy. pin 6 is wired for ground and the one end of the .004 is also tacked to ground. It seems as if the tube is not conducting by why with a 1 meg it calls for 10 meg. If I try a 1 meg across the other 10meg it works very little bad picture and no response from vert hold or size. All this changes with the one resistor at 4 and 6 . I can't measure the voltage on the plates of the 6sl7 with a Dvom I won't get an accurate reading but measuring I do get a reading of 120 Vdc and 75 Vdc the SAMs shows a lot more so my meter won't tell but changing that resistor to a 1 meg I'm thinking lowering that resistor seems to allow the tube to conduct with possibly low voltage on the plates but the screen is super bright. The plates get voltage from the hv with the resistors which check ok. This is nuts already, I'm open to anything at this point

Last edited by timmy; 03-23-2017 at 11:23 AM. Reason: Added more info
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  #69  
Old 03-23-2017, 12:18 PM
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Have you tried a different 6SL7? Possibly this one has grid emission.

Could there be a carbon path in the tube socket between pins 5 and 4 that is pulling the grid more positive than it should be?

You really need to get better voltage measurements... can you get another HV probe or fix the one you have?

jr
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  #70  
Old 03-23-2017, 01:15 PM
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Quote:
Originally Posted by jr_tech View Post
Have you tried a different 6SL7? Possibly this one has grid emission.

Could there be a carbon path in the tube socket between pins 5 and 4 that is pulling the grid more positive than it should be?

You really need to get better voltage measurements... can you get another HV probe or fix the one you have?

jr
I tried several 6sl7 no change as for my hv probe tossed it last year could not fix it. Carbon path , well anything is possible but I need to find out how to know if there is a carbon path taking place befor I get into changing that socket. Do you have an idea how to determine if there is a carbon path. I don't here anything arcing nor do I smell any corona from hv. Pin 5 SAMs shows 320 Vdc and I find odd that the 6.8 meg at pin 5 gets warm but the other 6.8 don't.

Last edited by timmy; 03-23-2017 at 01:26 PM.
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  #71  
Old 03-23-2017, 01:28 PM
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I would unsolder all of the connections to either pin 4 or pin 5 and mesure resistance between the two pins... leakage as high as 10 meg or so could mess up the bias on the tube.
You really need to get another HV probe, as low HV could be te main source of the problem.

jr
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  #72  
Old 03-23-2017, 01:37 PM
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Quote:
Originally Posted by jr_tech View Post
I would unsolder all of the connections to either pin 4 or pin 5 and mesure resistance between the two pins... leakage as high as 10 meg or so could mess up the bias on the tube.
You really need to get another HV probe, as low HV could be te main source of the problem.

jr
I thought maybe low hv but the crt is super bright and I tried adjusting the ring on the 1b3 and of course no change. Should the tube remain in the socket when I remove from one pin and test?
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  #73  
Old 03-23-2017, 02:33 PM
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The tube shouldn't make any difference, unless it is the cause of leakage... try it both ways. You could also check the tube itself for any leakage between pins, but since you have tried several different tubes without changing the symptoms, it is unlikely that you will find any leakage unless they all have the same fault.

jr
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  #74  
Old 03-23-2017, 06:30 PM
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Timmy,
Did you ever try spraying any cleaner into the vertical hold and size control to see if it would stabilize the vertical roll? Did you try wiggling V9, V11, or V12 while the set is on to see if it helped? I come across worn and dirty contacts all the time in old equipment. The cause of all sorts of issues. Just because parts are swapped or tested doesn't always eliminate the root cause.
Do you understand how the vertical feedback loop works with this set? If you have a scope, check to see if you are getting the proper trigger signal to your vertical oscillator grid from the sync separator/ integrator network.
Ed
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  #75  
Old 03-23-2017, 07:31 PM
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Quote:
Originally Posted by EdKozk2 View Post
Timmy,
Did you ever try spraying any cleaner into the vertical hold and size control to see if it would stabilize the vertical roll? Did you try wiggling V9, V11, or V12 while the set is on to see if it helped? I come across worn and dirty contacts all the time in old equipment. The cause of all sorts of issues. Just because parts are swapped or tested doesn't always eliminate the root cause.
Do you understand how the vertical feedback loop works with this set? If you have a scope, check to see if you are getting the proper trigger signal to your vertical oscillator grid from the sync separator/ integrator network.
Ed
I did spray the verticle pots in the beginning thinking it would help but it didn't and yes I moved v9 ,11 , and 12 , nothing helped and I don't have a scope I'm an auto tech, lol so I wouldn't have that for a tv but I have 4 other of these sets I have done and never came across something like this I mean these sets are kind of simple but this problem is kicking my ass. I replaced every mica in the vert and horiz along with all the wax caps were done. After the wax caps fired up and the vert went down hill fast and since then I did the Micas one at a time to hoping to find the one culprit but after replacing all I'm still left with this problem. I checked to see if any carbon shorts in the 6sl7 socket and none showed up. And all the 6 kv caps new also. Just don't get what's going on I am out of areas to check. In the beginning it seemed like a resistor went up fast but I only found one 2.2 meg that went up to 22 meg so I changed it and the 2- 6.8 meg resistors at the 6sl7 measure around 7.5 meg not all that high since I think my other sets were around there to but they work . And thinking one was breaking down in circuit I subbed them and still make no difference. I also subbed the vert size and hold pots no change. And also moved v10 the oscillator no change.

Last edited by timmy; 03-23-2017 at 07:58 PM.
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