How do I use a Sony All In one monitor as a monitor for a second pc?

[PigeonMan]

Hi, I am using a Sony All-in-one (SVL24145CXB) and I am trying to use it as a monitor for another PC, the all in one has 2 HDMI ports, an input and an output, but there are no buttons or options to make it work. Are there ways or programs to let me use the all in one as a monitor. It has to be through hardware so that my other PC can use it optimally, like getting 60 fps on CSGO.

 

[Barty1884]

With an HDMI input and an HDMI output, this Sony computer can output 1080p content and can be used as a NTSC/ATSC hybrid TV tuner powered by Sony BRAVIA TV technology.

Doesn't appear the HDMI 'in' allows it to be used as a monitor, it's there for use as a TV tuner.
https://www.bhphotovideo.com/c/product/972926-REG/sony_svl24145cxb_vaio_l24_series_24.html