Reinstall the motherboard drivers, inlcuding the audio drivers. Then reinstall the gfx driver. (Make sure to download the latest version of the drivers from both manufacturers. We don't want the old buggy drivers this time)
With most new motherboards you can plug in headphones, microphones and speakers in any of the audio ports, and your PC will sense what type of device you have plugged in and where.
It sounds like your driver wasn't working properly when your PC crashed because you plugged in the earbuds. I can only guess the crashing corrupted the gfx drivers too, so I'm hoping that reinstalling drivers will fix things.
I hope it works, because that's all I can think of.