I recently purchased a TCL 49S405 and have been pretty happy with it given its low price - obviously there are better options out there for people who can spend a bit more
I hooked it up to my computer, enabled PC mode on the TV, and made sure my PC was outputting RGB color. I then opened up the chroma subsampling test pattern from Rtings (I can't post links, sorry) and while it looks like there is no chroma subsampling, I did notice something else that was strange. Specifically the part of that image that has grey text on a black background was showing the grey text as a mix of grey, purple, and green, instead of just solid grey. I've attached two pictures showing this - one from far away and one close-up where you can see the individual pixels. Is this some sort of panel defect, or is this expected? I've displayed the same image on some IPS computer monitors and the text is solid gray, so I'm wondering if this just has something to do with the VA panel on this TV. I've also tried displaying this image on the TV from two very different computers (a Windows 10 machine with NVIDIA graphics and a Chromebook with Intel graphics) and get the same green and purple colors mixed in with the grey, so I don't think this is a graphics card or driver issue.
Additionally I'm getting a moderate amount of color banding on the TV, especially with darker colors. I've had a difficult time getting a picture of that but I attached one picture where the banding is fairly visible in the darker greys - I'm using the gradient test pattern from Rtings. I'm unsure if that might be related to the other problem in any way or if it's just expected from a budget panel like this.
Thanks so much for your help!