Check your battery, power supply/charger, does it charge?
Does it crash with and/or without charger connected?
Check your hard drive by the manufacturer´s tool. like seatools for seagate or wdlife for western digital or equivalen
check temperatures while running your laptop, in which situations does it crash
check ram by
https/www.memtest.org/#downiso use the usb autoinstaller and boot from the created boot stick