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  #16  
Old 06-03-2014, 07:44 AM
rodmonster's Avatar
rodmonster rodmonster is offline
Woodbridge, Virginia
 
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Location: Woodbridge, Virginia
Posts: 69
Update!!

OK...
So I had the repair guy come back. He popped the back and worked on several things (checked tubes, resoldered endpoints to the power tube for the AGC area, cleaned off some areas hat looked dirty from time, etc). He was there for 2 hours messing with things. It stabilized once or twice then back to scrolling. In the end he gave up and said if I could find a new Horizontal Oscillator Tube - that might fix it.
After he left I turned it back on to see what I could do. It made a popping noise for a few seconds... the picture jumped back and forth and then it came in... clearer than ever.. I was like - huh... what the heck... turned it off and back on.. still there.. I figured well this is nuts but I am ordering the new tube anyway.
Over the next two days I watched the TV for up to an hour at a time as I was working on things in my toy room. Figured if it stopped working - then so be it - I would have a new tube soon to fix the horizontal issue. Well it worked just fine.
I got the new tube last night... (and it was new - old stock - in box - never been opened and it was OEM from Sylvania). Once in - it took a few minutes to come up.... and then the scrolling started... I started adjusting the Horizontal hold, AGC, height, etc.. and it kept going... Worked on it for nearly 2 hours and thought... this is nuts... its a new tube... ok.. well.. I am going to throw the old one in for kicks and giggles...
As soon as I put the old one back in - it stabilized again - without ANY additional tuning.... And I watched it all night as I was in the room - without any issues...
Will it last? I don't know.... Did he do something that inadvertently made it work now.... I don't know...
In the end - it is working and I am pleased as punch!
See pic below...
On a side note... I found a 1977 Du-All Sears 8mm projector over the weekend... took it apart , replaced the belt, reattached old gears, lubed it up, and got it up an d running! =)
Thanks for all the help Yall!!
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Last edited by rodmonster; 06-03-2014 at 08:03 AM.
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  #17  
Old 06-03-2014, 08:41 AM
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sampson159 sampson159 is offline
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Location: columbus,ohio
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hope it holds up for you.this is the set that put sylvania on the map.they made the best picture at the time.electronics were fairly simple and worked well.the crt was the crowning glory.on the showroom floor,these sets always got the nod over the others.even the zeniths!they are scarce and glad you have saved this one
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  #18  
Old 06-03-2014, 10:48 AM
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DavGoodlin DavGoodlin is offline
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Location: near Strasburg PA
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If you have the scrolling sideways, it often means the sync pulse is getting interrupted. This drove me batty with a set I had in high school, long ago.

It happened on a 1965 RCA color set chassis CTC16XL, and I replaced several tubes then horizontal AFC diodes (described by Davewm) with no improvement.
Then, with no outside advice, I replaced the HV rectifier tube which WAS a newer Sylvania 3CU3 with a new-old-stock 3A3 and the picture locked solid like never before. My conclusion is that the 3CU3 was shorter and did not seat fully into the flyback as RCAs do.

So, your problem could be some very mild and intermittent arcing, possibly at the HV rect tube or tripler block, if this set has one instead of a tube. Either way, its on the AC side, not the DC side after the rectifier/tripler that goes to the picture tube anode.

Keep the back cover off, HV cage open and when the picture "goes flopsy" turn off all the lights and look for some purple glow along the lead from the HO tube, into and around the flyback and HV rect tube. Clean up and RTV silicone the area that is arcing.
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  #19  
Old 06-03-2014, 07:36 PM
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Electronic M Electronic M is offline
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If it is a D16 then no HV cage or rectifier tube (uses a tripler instead). The backs of those sets have decent ventilation and given all the toys in that room if a kid gets in there they might not hear you tell them not to reach inside the open back of that TV. The terminals on that tripler are at about 6KV when running IIRC...Better to keep the back on when not fixing it IMHO.

NOS does not always equal good in tubes. EVEN when new there were always a good percentage of tubes that were factory duds, and THAT was ~40+ years ago!...Tubes ain't like milk, but they are not exactly like wine either. Age just marginally increases the chance of pulling a dud from a batch of NOS tubes. If you are curious find a local (radio/TV/audio) collector with a working tube tester and see how that NOS replacement tests...I'll betcha a cookie it is either weak or leaky/shorted.
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  #20  
Old 06-04-2014, 10:13 AM
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rodmonster rodmonster is offline
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Quote:
Originally Posted by Electronic M View Post
If it is a D16 then no HV cage or rectifier tube (uses a tripler instead). The backs of those sets have decent ventilation and given all the toys in that room if a kid gets in there they might not hear you tell them not to reach inside the open back of that TV. The terminals on that tripler are at about 6KV when running IIRC...Better to keep the back on when not fixing it IMHO.

NOS does not always equal good in tubes. EVEN when new there were always a good percentage of tubes that were factory duds, and THAT was ~40+ years ago!...Tubes ain't like milk, but they are not exactly like wine either. Age just marginally increases the chance of pulling a dud from a batch of NOS tubes. If you are curious find a local (radio/TV/audio) collector with a working tube tester and see how that NOS replacement tests...I'll betcha a cookie it is either weak or leaky/shorted.
Oh yeah! Sorry - I didn't say that... I did put the back on after changing tubes... =)
I have a place I am trying to get to in a neighboring city that has a tube tester. I plan to check them both!
=)
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  #21  
Old 06-04-2014, 02:19 PM
Gunslinger Gunslinger is offline
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the problem with older tv's being used with VCR's is horiz sync. It is called "flagging" The horiz time constsnt is too long and needs to be modified to change the timing. Don't ask me how to do it but you can probably copy the circuit from a later set. When Vcr's first came iout, RCA and Zenith modified their replacement horiz modules.
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