ram issue 3 beeps with disfigured screen.

Hi guys, I tried searching around for the issue I'm having , but it seems mine is a bit worse than usual.

So my Mac pro will beep 3 times which i searched is the ram issue. But some time it will boot up and less than one minute the screen will dis figure and freeze.

Trouble shoot done

Replaced ram

Taken out one ram at a time

Brought to apple store, they do not know the issue and want to charge $600 to have the board replaced.

Can anyone help me out ? I understand it is out of the warranty period, but $600 is out of my budget. And being honest I did not expect this will happen to a Mac book pro within 2 years

Thanks in advance