Connected TV Haier K6500SA 24'' to PC. At first everything was fine, then the image itself became grainy. Why?

Question

Computers

Hello. My request will be slightly unusual because I use the TV as both a TV receiver and a PC screen. And the essence of the problem is this: I connected this TV (Haier K6500SA 24'') to the video card (first to Geforce 630, now to Geforce GTX 1050, without ti, I have it connected). Both at 630 and at 1050 the same problem - for a long time everything worked perfectly (even after updating the firewood and everything else), and then suddenly, for no reason, the image on the TV became fuzzy. Or rather, how, it is almost not noticeable. That is, it is visible in small print, but not in images (static or moving). The font became, as it were, with a shadow or doubled a little. For the eyes, frankly, unpleasant. I poked around in the settings of the video card firewood, poked around in the TV settings, and did not understand where to fix it. A couple of times I managed to fix it, but for a few days again (I have a bad memory after an injury, I forget where I ticked, for example). I tried the Windows cttune command - it does not help. Scaling on the video card twisted - also to no avail. I changed the HDMI cable - also did not help. Please tell me what could be the problem, so that I can definitely solve it once and for all. Thanks in advance.
I'll add: a SyncMaster 794mb 17'' monitor is also connected to the video card. Everything is always good with the image there, that is, the conflict is with the TV with the computer's video card. And once again I’ll pay attention: at first, with the same connection of the TV to the PC, the image was clear. So, it's not about him, but about some of the settings.

Answer 1

See the output signal frequency and synchronization protocol.
(everything in the map settings)