Help to solve a mistery

Dear all,

I am new here.

I am searching an explanation for what is happanening on my monitor.



You can see in the image what I can see on it when it is off.



I deleted/cleaned the glass surface with all kind of cleaner, also spirit.

But after some days it appears again.



It seemes to be traced with a finger, but it is so geometricaly perfect that it would be impossible. Moreover nobody can access to my studio.



This symbol remember me something, but I cannot localise it.



Has somebody ever see something like this.



Many thanks.

Luigi

acuallty no idea!!

Welcome to the forum!
What kind of monitor is that? LCD or CRT? That pattern is centered on the screen or its position is exactly where you draw it?

Hi and thanks for your welcome.



It is a CRT monitor Acer 17 " G772 (BTW I also mailed the question to Acer and I'm waiting for some answer, if any. The pattern is similar to that in the figure, maybe larger.



It could have something to do with the smoke of my pipe, as it was attrracted by stati charge on the monitor surface. (?)



Thanks to all,

Luigi



p.s. my glasses are clean and I shown that to some friends

good question, CRT or TFT???

What happens if you degauss the monitor just before you turn it off?

nothing

Do you have some other equipment near the monitor (fan, speaker, etc.)?

If that pattern were exactly in the center of the screen, then it could have some explanation. If the electron beam isn't cut-off at the moment of turning off the monitor, then for some time the whole dying-out beam is concentrated in a small spot in the center (just as it happened in very old tv-sets) because the deflecting coils are no longer powered. That concentrated charge could then attract small dust and smoke particles to that area.
So in this case it's a minor fault in the monitor's electronic circuit.

I already examined all contingent possible causes, but even if my little desktop is full of electornics, the problem is that nothing has changed in the last 2 years, when I bought the monitor, and this symbol appear only since a 3-4 months!



In the mean time Acer answered telling me to address/bring the device to... some 300 km from here to make a test



I know that this sounds a little "The Others" or "do not open the door", but I am really curious to discover the mistery!