Since about a few weeks ago, my studio 1558 is not functioning properly. Sometimes on startup there is just a black screen; I can hear the whirring sound of the fan and processor, but nothing is on the screen. Sometimes it would start up, but in black and white. Most of the time it starts up with a green screen; a mesh, like a green net, gets displayed over the screen.
Also, while running, the green screen would suddenly appear and the screen freezes. I think the problem is my graphics card, but how do I test it?