LCD temperature boot problem

From one day to another computer monitor has stopped working properly. CHIME is heard but not seen the white snapshot start. Also does not connect the keyboard (even USB) so I can not start the session.

Can the graphics card cause such a problem (not able to connect to mouse and keyboard)? Does the display cause this?

I dont want to buy another display and find out that It wasnt the problem.

Is there any way to start a session without keyboard or mouse. I need to check if I can use a external screen, to see if the computer still work properly beside the disply matter.

Any ideas???