Recently I went away and came back to find my pc had been left on all that time, I turned pubg on and the game crashed along with sound glitches so I turned my pc off to stop over heating, ever since then when iv turned my pc on the fans have come on along with the cpu cooler fan but it won’t post and the fans sound something like a slow moving train as they speed up and slow down, along with the leds flashing when it slows, could anybody suggest what to do?