[muppy03]

Just testing your knowledge here guys.

I have an old TV here must be about 10 years maybe more. It works fine and dandy except for one small problem. Now I dont need it fixed but very curious as to why it does what it does.

On one channel and one channel only, on certain commercials usually ones that are done in mainly black or white (writing, red bull ads etc) it makes a shocking static noise.

The question is why does it only do it on one channel and why only on commercials?

On another channel the same ads play fine.

As I said I dont need a fix just very curious.

Thanking you

[JohnWill]

Well, the snapping sound is probably a HV arc. I've seen sets do that when the picture changes suddenly, usually when they're pretty dirty and there's a place for the spark to jump. The 20-25KV anode voltage varies quite a lot with brightness changes, maybe for some reason the high contrast ads just push it over the edge. The first RX would be to simply blow the dust out of it.

[n2gun]

note of caution!! if you do decide to blow the dust out, even if the set is unplugged the 25,00 volts is still there.