I think my Raspberry Pi B is dead, is there any way to be sure?

I think... I'm not certain. It still shows up on my router page as online and the light on the power supply is on. But there's no lights on the device in any fashion, not even when applying the power. It was working just fine yesterday. I was having issues with it staying online a while ago, but I thought i fixed that by buying a new SD card.

I only use it for torrenting, would that kill a Pi? I don't even write files to the SD card.