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#1
06-25-2010, 04:37 PM
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loud snap, temp blue tint
This is on my sylvania SS set
everynow and then I will get a loud snap sound, enough to startle you, and the the pic gets a bluesh tint, that quickly fades away and is back to normal, maybe 30 seconds tops. Of course I can look for it with the back off for hours and nothing will happen, then I will look away for a min and "snap"... any ideas on what may be going on? 
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#2
06-25-2010, 04:48 PM
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Hmmm, check the CRT for shorts in the blue gun. Also meter the drives to the CRT pins. Also could be anode arc. That would explain the loud snap. I think that can mess with drive voltage as well. Discharge the CRT and clean the aquadag and anode cap and see if it still does it.
__________________
Honey, turn on the tv.. I'm cold!
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#3
06-25-2010, 06:15 PM
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the HV lead off the anode button has a plastic stand off, but further down the lead it come directly into contact with the metal CRT shield, and it looks a bit blackish right there. I am going to wipe that off, and get a closer look at it. Will also make up a little card board stand off to get that away from the metal shield.
there was a large amount of dust all around the rubber anode boot as well. seems like a red substance is sealing it to the crt. Question about a CRT short making the snap, would not an internal arc be silent, inside the high vacuum of the CRT?
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#4
06-25-2010, 06:30 PM
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I had a SS 1970's Philco that would make a loud snap now and then, it would ruin the CRT in a month or two.
Turned out to be a bad CRT socket arcing over from the Focus pin, essentially "rejuvenating" the tube over and over until the cathode was stripped.
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#6
06-25-2010, 10:06 PM
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Ok I could see the focus lead coming out of the socket, and going right by a resistor lead on that pcb.
I dressed it up and away from the board as soon as it exits the socket. watched it for about 30min, no snap. I will be checking the crt in a bit and see how well it tracks.
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#7
06-25-2010, 10:17 PM
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Iguess it would not hurt to clean that up real well and maybe put a dolup of silcone right around that lead where it exits, that would also help maintain the lead dress.
IIRC the one time I was close to it, it did seem the sound came from around CRT socket/pcb.. I did not see it but "think" that was the area. I sure dont want to see my nice sylvania black matrix tube ruined. I did notice the grayscale was a bit bluer than it should have been when a B&W show came on.
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#8
06-25-2010, 10:20 PM
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In color TV's of this era, arcing and/or snapping usually comes from one of three sources: The CRT anode, a cracked HV tripler, or the CRT socket. From what yours is doing, I'd say it's the socket. You may can take it apart and clean it; but, I'd probably replace it just to be on the safe side.
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#12
06-26-2010, 09:11 AM
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searching on line for sockets, everything is coming up from china... 1.50 for socket 25 for shipping...
anyway, I was looking at the schematic, there is a built in spark gap at the cathodes says "spark gap part of CRT socket" now I am concerned, I not only have to locate a CRT socket, but have to find one with a built in spark gap, and on top of that there is no part number in the sams.
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#14
06-26-2010, 02:57 PM
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we had that issue back then.you can take a socket from anything and wire it in.did more than a few like that.a little ackward getting the back on it,but it works and makes it really easy to service.they seem to arc on that focus pin.also,there should be a plastic grommet that holds the anode.mounted on the degaussing shield.what ever you do,dont let that ruin your crt!
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#15
06-26-2010, 04:17 PM
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