My pc is start automatically when power switch on

:hello:

System specifications?

Does it start automatically and stop the first time the PSU is plugged into the wall and switch on, or does it start automatically and continue to boot?

Does it shut off properly?

If it start automatically and continue to boot or does not shut off properly, I think you have a bad PSU. Try a known good PSU of similar capacity.
 

Paperdoc

Polypheme
Ambassador
Maybe also check the front panel push button switch for on / off. It is supposed to be only a momentary-contact switch. But if it is always contacting (faulty, or mechanically jammed in) it will appear to be pushed as soon as power is supplied and will cause an immediate start.

Any chance the connection from the front panel to the mobo pinout have been made wrong?