sony vaio tech problem

Hello,
My lap top has been 'broken' for a long time now. There is a switch at the top which allows user to swtich between stamina and speed modes. I do not know what they mean, but i do know it shoulc be on speed, like it was originaly. on my laptop i am no longer able to switch to speed mode, because everytime I do that i am unable to read the screen, everything is covered in strange lines and fuzziness.
After speaking to some poeple who know about computers, such as the vaio experts, it has been concluded that the problem is with the video card.
I have tried many different solutions to try and fix it, but nothing works....
I dont want to send it to Vaio to be fixed as its very expensive and i need to lap top with me. (which works fine in the stamina mode by the way, i am guessing all i am missing is the graphics).
Can anyone help me with this do you think?
I appreciate your help in advance ))))