I tried going into recovery mode...but the problem with that is, I can't see what I'm doing.
I haven't tried a non-HDMI cable (can't find it for the life of me)
Also, I neglected to mention I'm using a HDMI switcher(?) to switch between cables (TV -> Xbox, TV -> PS3, TV -> Laptop); I didn't mention it because it's probably not the problem, but I figure I'll mention it now just in case.
Lastly, sorry for the late reply.