Question Pc on but keyboard and mouse and hdmi doesn’t work

[A56br6]

I changed my case and got an ssd but when i turned on my pc it turns on but when i run any game it restarts i changed my power supply from 550w to 700w and when i finished everything my pc turns on but nothing on the screen and mouse and keyboard are off except the mouse pas is the only thing on, i tried connected only the mouse and the hdmi but the mouse leds turns on when i press the mouse, j changed the cmos battery like 5 minutes ago but the same problem is happening, oh yeah before changing the power supply there was a erid buzzing sound on the mother board, and when i searched for a solution they said to get rid of the noise unplug the speaker, i know its not the right thing to do but i’ve done it to get rid of the sound, anyway the problem in facing right now is that my pc turns on but the monitor and keyboard and mouse are off

 

[NightHawkRMX]

Full system specs?

Ensure all connections are plugged in.

If still nothing, try the old PSU.

 

[A56br6]

Full system specs?

Ensure all connections are plugged in.

If still nothing, try the old PSU.

I5 8400
Rtx 2060
2ram sticks one is 8g and the other is 16g
Gamemax psu 700w
Motherboard: msi h310m pro-vh

 

[NightHawkRMX]

Oh dear. Not a Gamemax PSU.

That belongs in a trash can, not a PC.

Try your old PSU.

 

[A56br6]

Full system specs?

Ensure all connections are plugged in.

If still nothing, try the old PSU.

the old psu works but i can’t launch games because it is at the limits,

 

[A56br6]

Full system specs?

Ensure all connections are plugged in.

If still nothing, try the old PSU.

Oh and by the way i had a few of problems while i was building my pc in the new case so i truned on and off the pc too much, so could restarting too much lead to ruining some parts ?

 

[A56br6]

Oh dear. Not a Gamemax PSU.

That belongs in a trash can, not a PC.

Try your old PSU.

Why is it trash ?

 

[NightHawkRMX]

So the old PSU works and new one doesn't.

Ensure all cables are connected properly. If they are, try PSU paperclip test to see if the PSU fan spins.
https://www.wikihow.com/Check-a-Power-Supply

 

[NightHawkRMX]

Why is it trash ?

Because its Gamemax. They sell PSUs with very very poor quality and have a reputation for being horrible.