News from dookie

I`m having some gnar power related computer issues. a couple of days ago my computer randomly turned off without shutting down while I was in the middle of doing something. I restarted it and it didn`t even complete the booting process. I would imagine that it`s a power supply issue, but i`m not quite sure. there are some files that weren`t backed up (silly me) that I must retrieve. I`m wondering if it`s a simple issue that can be fixed with an inexpensive new part or if I have to bring the hard drive into a computer shop to retrieve the data files. thanks in advance for the help! it`s greatly appreciated.