ps3 has no output and shuts off after 20 seconds

I turn on my ps3 and it seems like it freezes at the beginning because i cant turn it off. No TV output after trying different hdmi and even composite cable. I changed TV’s and hdmi ports as well and none worked. I removed hard drive and cant get to recovery. I tried to reset resolution by turning it on (holding) until i hear second beep but only beeps once. After the second beep it just forces the shutdown. If i press it once it turns off by itself after 20 seconds. I used a heat-gun and ans headed the cpu and gpu and still didn’t work. Fans do spin and console is clean. I messed with the two white screws from the power supply and it still didn’t work. What I might try is changing the power supply. Light is green when i turn it on btw. Any help would be greatly appreciated. Love y’all and take care.