https://support.playstation.com/s/article/PS3-HDMI-Picture-Problems?language=en_US

This is the third such thread you’ve started with this issue:

https://www.speedrun.com/Speedrunning/thread/ekg0l https://www.speedrun.com/Talk/thread/vf2js

All the previous times you’ve gotten answers and in the second one you stated yourself you solved the problem. Are you having the same issue again?

Additionally, we’ll need more information to help you. Are you using a capture card? Are you using HDMI, Composite, Component? Are you seeing a signal on the TV and not the computer? There could be many reasons for signal not showing up.