Hi all,

Novice question maybe! I was mounting a power strip under the window sill behind my 1966 RCA CTC17 and noticed that the wall behind the curtain had turned a dark blueish color, which seems to have come from the set. TV is in the corner, angled, with a good 6+ inches between it and that section of the wall. It wiped off for the most part. Set stays cool since I have a fan clamped internally, aimed at the flyback, so this can't be from excessive heat. The fact that it is blue strikes me as strange. Even weirder, the white curtain is not stained, only the wall behind. Was definitely not there before so pretty sure set is responsible. Thanks!

Jim

Is the HV cage open or does it have extra non-factory holes? If so then it could be X-rays especially if the HV is on the high side.

I don't know if a color set emits enough X-Rays to discolor a wall but high voltage does attract dirt, possibly heat is affecting the wall as well?


Edit, just noticed you have a fan mounted in the set, it's almost certainly attracting dust, since it wiped off this is probably what it is.

Thanks, guys! But the fact that it passed through a thick white curtain without discoloring makes me think it's not dirt or dust. Xrays sounds scary, should I be concerned about that with the CTC17?

no.

I'll watch the area and see if it returns, then go from there. Thanks, all.

I'd be more concerned that it's Mold, the curtain may be trapping moisture in that area.

The only idea I have is the HV section of the TV acting as something like a "negative ion generator", or similar. They sold such gadgets back in about the 1980s (from Sharper Image and other similar places) as a type of air-improvement device if I remember right. Supposedly, they could attract dirt onto the wall behind the device, and the device itself had some kind of high-voltage circuit to generate negative ions.

Two possible causes for the blue stains come to mind.

My first thought was the high voltage and the resultant corona in the TV can and do generate ozone, which is a very powerful oxidizing agent, which could react with something in the paint.

I promptly wrote this off, as the ozone would first have to pass by the white curtains, and that would leave them dingy.

This leaves the second possibility, as Eric H suspected, mold resulting from moisture penetrating the wall near the corner where the TV is.

If this happens more rapidly in the winter than in the summer (unless you live in a very damp region of the country), this is another clue that the problem is moisture being protected by the curtains and that moisture causes mold.

Based on your descriptions, mold from excessive moisture is the most probable cause.

Look behind other curtains in your home and see what you see.

Look behind other curtains in your home and see what you see.

But ignore that man behind one of the curtains, he's just the IT guy trying to fix the servers... :D

Look behind other curtains in your home and see what you see.
Most likely cats if you have them.