Quote:
Originally Posted by Username1
I would like to know if you retested the old tube after removing it? and if its shorted, can your tester remove the shorts? is there any physical damage to the old tube?
If you can clear the short, reinstall the tube, make a new you tube video of the back when you power it up, and see whats sparking. Is it on the socket board? those things had ground wires too, is it on? is the B+ around 125 - 155? does this tv have a trippler? I don't think so, but had to ask. You know its possible you have a bad yoke now... Not really likely, but you need to look at what the sparks could have jumped to. I think its pretty strange you have a bad tube now from that unpowered discharge on an 80's sanyo.
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The old tube ended up cracking in the neck after gently tapping on it trying to see if it affected my G1 short reading. So it is now gone to air. That tube is no more. I even busted the end off afterwards and pulled the electron gun assembly out and cannot see where it may have shorted. This is why I needed a new tube.
Just FYI, when the old tube was in there after the problem happened, the TV ran for about 10 seconds before I shut if off after seeing the neck lit up bright purple and buzzing (wondering why I wasn't getting a picture.) There were no HV arcing anywhere. Everything just started up normally other than that problem in the neck.
Now, I tested the TV with the new tube without the HV 2nd anode lead attached. Everything works just fine. Heaters light, everything else is hooked up including all grounds as I've mentioned above (I've checked it 4 times now. With 3 different CRT ground wires, they are all hooked up to their appropriate terminals. I took pictures and took notes before I even disassembled the set.) Everything functions as should be without HV hooked up at this point.
I bought an HV probe meter off Ebay, should be here next week to check the high voltage which should be around 30KV.
All that aside, the only thing I can think to do is try it again. I hurried up and pulled the plug on the first loud snap. After one to two seconds the tube discharged again making that second loud snap. It also scared me because the screen also lit up with it. But if you listen carefully, it also had a bunch of smaller, normal sounding snaps you'd hear upon starting up and shutting off the TV.
I've just never encountered this kind of problem before. If everything works without HV applied, could there be a problem internally with the second anode connection? As in this NOS CRT is defective? Everything else checks 100% on my Sencore tester. The loud snap/pop was internal to the tube, and caused it to light up as well as you may have seen. I had the yoke out after this incident and there are no burn marks or other indications of a failure. There were no burning smells or ozone either after this happened.