View Full Version : CRT short question


kramden66
03-09-2013, 01:42 AM
I was testing some crts on sets a guy might sell , i encountered one where on my b&k 465 the g1 light goes on , there was no emmisions and the tube didn't light up , this shows in the book as a k to g1 short , the crt looked like it might have tape around the base but it was tough to tell with the light level , i can investigate that further , so could it be the base is loose and when it was taped a wire is touching another or is something else going on inside the crt ?

mike

Geist
03-09-2013, 08:15 AM
Hi All;
It could be either or both or something else.. Yes, It very well could be that the base is twisted and has a short and you might get lucky if it is.. It could be easily fixed.. Yet, it could . also be an internal short, and possibly it could be eliminated. with the right equipment.. The question would be why the internal shorted..
THANK YOU Marty

davet753
03-09-2013, 09:10 AM
I can't remember the model of the B&K tester I used to use, but it was from the 80's and it had a switch marked "remove shorts". If the indicator light came on for internal shorts, I found they could usually be cured by tapping lightly on the CRT neck with screwdriver handle while pushing the "remove shorts" button.

Quite often during the rejuvenation process there will be something blasted off that ends up shorting something, but it can most always be fixed.

Tubejunke
03-09-2013, 08:02 PM
I am not familiar with the B&K setting and indicators, but I have had many tubes with a loose plug and the often poorly soldered pin connections cause an open as opposed to a short. Often people will figure this out and wrap tape around the neck and plug while holding it in the "sweet spot" where the heater circuit is no longer open. This usually works for a while, but also usually comes back to haunt someone later on down the road.

I would get a soldering gun and heat each pin one by one and allow solder to draw up into and fill the void inside the pins. I say to use a gun as a gun will provide enough heat to heat the plug pin as well as the wire CRT lead that lies inside enough to get a good electrical connection. Cold solder joints are one of the most common problems there are and they often have a decent mechanical connection or the appearance of being bonded when in fact they are not bonded at all. Sometimes the flux will actually harden and bond two wires together with almost no continuity, or none at all.