No video after replacing thermal paste

I have replaced thermal paste for my ps4 a week ago and afterwards it worked perfectly fine. Ran quieter, better heat exhaust, etc. But after a couple days of it running perfectly, my TV no longer gets a signal. When I turn the ps4 on a blue light flashes for a whole which eventually turns white, which if I am correct is how it normally boots up. I am just wondering if I might have messed something up or if it could be a problem with my HDMI and how to fix it.