LINK-MI TV04V 90 Degree Rotation Vertical Video Wall Controller 2x2 HDMI+DVI+VGA+CVBS+ATV+USB Image Stitching Splicing Processor

Can this unit process a 4k input (3860 x 2140)? I understand the output will be 1080p.

is this one support "0 degree" with 3 or 4 monitors (normal scene. not rotation)?

What is the best tv size recommended for 4 tvs to get the best picture quality? example if i use 4 50” tvs vertically would people look fat or normal

We bought one of these in aug 2018. it is not turning on. we suspect it is the transformer/power supply cord. can we buy that from you?