You were smart to back up your data. Things like this happen unfortunately. I'd take it to a shop for repairs or just buy a new laptop. Repair shops are expensive. One I frequent charges $70 just to take it and tell you what's wrong, so it could easily cost you a couple hundred bucks. If you're lucky, it could just be the hard drive, but if it's the motherboard, the cost could be more than the laptop is worth.