My Odyssey x86j4105 freeze so often!

I installed ubuntu 20.04LTS to my odyssey x86j4105, but my computer frozen so often . so I reinstall it, but computer was still frozen. I tried to install ubuntu 20.04 server version, but it still freeze what should I do?
ps. Also sometimes pc doesnt turn on at once. when I turn on it, switchs light is on but it turn off soon and didn`t work before I unplugged power cable. plz help

Are you using the correct power supply?

I use enclosed one. it`s there anything more fit to it?

That work fine, was just checking. Have you tried running memtest86?