It's hard to say... was the computer *completely* disconnected? No network cable, no modem line, no other powered peripherals (printers, monitors, etc.)?
You may have taken a hit that killed some component. Based on where you're describing it, I don't have good feelings for the life expectancy of your motherboard
You can take the monitor and put it on another pachine to make sure it's okay. You may have to have someone at a shop take a look at the computer itself. They should be able to check it for fried components.
BTW, this is the opportune time for my occasional plug of whole-house surge suppression systems. They're rated for far more power than any plug-in surge suppressor you can find.