Videocard or CPU or MB problem

[kryk]

Don't know if problem is in processor. My MB is ASUS M4A785TD-V EVO with AMD 785G/SB710. It has integrated videocard Radeon HD4200. I tried to unlock CPU cores and managed to get 3-rd one. I but 4-th didn't came out. Less with that.
But the problem is that after i installed GIGABYTE GeForse GTS250 (GV-N250-1GI 2.0) when i try to unlock cores there is no image on monitir. Acording to sound signal BIOS starts normally.
If anyone has some suggestions i would be glad to listen them.

P.S. Sorry for my english. It's not my native language.

[Dark Mantis]

Hi and welcome to the Gigabyte Forum.

I would suggest trying to go back a step or two and see what is causing this problem. At the moment it could be the graphics card or the processor. If you have the card you were using before you installed this one try replacing that and see if the problem still manifests itself.

Failing that try putting the processor back to the default state and see if the problem goes away. You need to find out what part of the system is causing it.