Your image is showing a DVI video connection. Not VGA - are you using the motherboard's VGA video port?
Motherboard User Manual:
https://download.msi.com/archive/mnu_exe/mb/M7A38v8.1.pdf
Verify that I found the correct User Manual.
Refer to the User Manual to double check
all connections and configuration settings.
Ensure that your GPU is supported and correctly installed and configured.
The intermittent working or not working could have other causes.
And those possibilities need to be eliminated.
= = = =
If the GPU/VGA problem occurs on another known working computer (your brother's computer) then your GPU has likely failed in some manner.
Is it possible to test your brother's GPU in your computer using a VGA connection to monitor? Determine if that works.
If your bother's GPU works in your computer then that, in my mind, is more evidence that your GPU is faulty.
(Note: your PSU is 550 watts. What make, model, and wattage is your brother's PSU?)
Likely no harm in taking the cover off of your GPU for cleaning and inspection. Be sure to do so via your GPU's User Manual.