MacBook mid 2012 fan spin sleep stays on

Hi,

Just a issue with my macbook mid 2012

no water damaged, no corrosion very clean

Sometimes it turns on and it works but this could be about 100 attempts.

Normally when i turn on my macbook fan spin normal speed and white sleep stays on

no external output

when i take out ram it beeps so it knows when there is no ram

i have tried the following

smc ,pram reset

changed ram with working ram,changed battery,changed charger

unplug all connections apart from lcd

Does anybody have any ideas( Looks like Logic board)