Why is my PS4 Pro Not Working?

When my PS4 Pro turns on, The fan is extremely loud and when i try to load into a game the PS4 Pro makes 3 beeps and turns off. and addition is that sometimes it will only Rev the fan really high, make the 3 beeps and shut back off(this is after i took it apart, and cleaned my PS4 Pro.) I also re applied the thermal paste to get the paste of the edges to get used(I'm not sure it it was too much, but no thermal paste was added, I only used the thermal paste that was already there.)