Take a photo of what you see on the screen, then take a screenshot on your laptop with the PrtSc button. Attach both here. This may help someone identify the problem you're having.
I am sorry for the problem at hand. Because the HDMI is controlled by the video card, I will recommend to get in contact with Sony so they can provide you with the best options, because the problem could be related to drivers, which you could remove and install latest drivers from the sony web site. Or could also be related to the HDMI port been damage.
Please verify with Sony for best options.