ok, post a picture, I'll put arrows on it to show you whats what...
Ok, tell me how old the pc is, and how old the graphics card is, what graphics card is it?
Honestly, from past experience, TELL YOUR MOM! don't try keeping it a secrete, coz that will only end badly for you. Have you overclocked you graphics card, or any other pc parts?
have you fiddled around with the pc in the last month?
i need to know all these things.
Oh, and i've been in a similar position to you, only i overclocked the shyte out of my graphics card and blew the darn thing.
How is the dust in your pc doing? by that i mean is your pc clean or is it just jam packed of dust, if it's full of dust, then you might have a problem