I don't know if anyone is still checking these old threads, but hopefully I can get some advice.
I got a used 34HS420 recently and after resetting all values on service mode I managed to get rid of overscan and bowing problems. There's still a bit of geometry problems on the edges but I can live with that (although it could be related to the issue I have).
The issue is that there seems to be a slight (very slight, only noticeable in light colors, especially white of course) redish/yellowish tint on the left side, whereas the right side has a light blueish tint (mostly on the upper right section). Sometimes it also looks like the left side might be a bit more stretched, or the left one might be more compressed. But things look a bit wider on the left side than on the right, that's for sure. Actually, the left side is probably the real problem as the stretching it seems to have also goes with blurriness/out of focus. It might also be worth noting that at some point the right side tint was worse, so perhaps it's something that can improve over time to some extent.
I'm not sure if that's a convergence, geometry, or purity problem, or magnets, or something else entirely, but it is noticeable and it would be nice if I could get rid of it. Could manually degaussing with a coil help at all?