First you say 'I completely unhooked my graphics card' and then you tell us you have onboard graphics
Then you tell us your surge protector 'blew up' and then that the on-off switch gave off a small electrical discharge. Describe the discharge. Static that you felt? Or did you notice sparking?
Which on-off switch? The Power Supply switch or the one at the front of the computer? And by surge protector I assume you mean a mains didtribution unit with surge protection. If so, what happened? Did a reset button pop out? A Fuse blow?
From the information you've given, I'm suspecting PSU fault but your outline of events seems contradictory. How did you unhook onboard graphics?