Color issue (stain) on my TV

Look at the power supply circuit, a "posistor" in the photo, it is round or rectangular and has three pins. Use the same model as the one on your chassis.

http://www.pointe-de-lecture.com/boutique/achat/index.php?catid=424

Only three solderings to do to fix this problem. This is very often the case.

re
I'm not a TV technician
but it could be related to the graphics card (or the part that serves as (...) or the tube if it's a cathodic screen
but also to the backlighting... hard to say
the fact that the TV is used with a console might be an important point too
try the TV without the console (in normal mode) for a day or two to see, but with equivalent on time
it's possible that a component overheats, causing the failure that stops when the component cools down
that will eliminate one possible cause (or it will confirm it)

hello
it doesn't smell good for your wallet

Hello.

Does this issue only occur with the PS3?
When you simply watch a TV show, does it work correctly?

re
review my message:
but it could be the graphics card (or part serving as (...) or the tube if it's a cathode-ray screen
but also the backlighting... hard to say
possible that a component overheats, causing the failure that stops when the component cools down
in any case, it doesn't smell good
what kind of TV is it by the way? Windsor? but a cathode-ray screen?

If it's not a flat screen, it's a cathode ray tube (CRT) screen.
The circuits that may be involved in your television are: the chrominance circuit, the degaussing circuit.
I'm waiting for your response to my question 6.

(Yes, I saw, our responses slightly overlapped).

The diverter can be detached or it’s a demagnetization issue. Generally, in this circuit, it is the CTP that is defective.

How can I reattach the "deviator"? I don't know anything about it at all.

Well, I don't think I'll do it myself since I'm a bit stupid when it comes to repairs, thanks for your replies ^^

Often this component is good but has overheated. So much so that it no longer makes contact with the printed circuit board.
Unplug the television and redo the three solder joints.

Thank you, Francoins, I will do that. Thank you very much for taking the time to help me because I really don't want to buy a new one ^^
See you soon ;)