RB 411GL problem

Hello everybody ! I have got a 411GL, freeze all the time. Working couple minutes, and then stop.
I tried different power supplies, the result was the same. I am using 6.15.
i do not know, this is a software or a hardware problem.

Anybody met this problem ?

What method of RouterOS 6.15 installation you have followed?

All single and detailed pass, please.

Hello, first i tried in the ROS system/packages/Check for updates menu, the installation was successful.
And yesterday i installed from 6.15 npk package.So far the problem is the same.Working 10 minutes, and then freeze.
Bootloader is 3.10.

So ? Any hints ? Ok, this board is going into trash. Unusable.