iPhone 5 Recovery Mode Refuses to Work.

My phone is an iPhone 5, it is an old phone but it was working very well before my phone died. When I went back to charge it -- it had the "support.apple.com/iphone/restore" thingy. I connected into iTunes and start downloading (restore data) and updating everything. After downloading/updating, the progress/loading bar was at 70-80 percent on the iPhone, but then it automatically tells me it failed. And in the exact words it says this: The iPhone could not be restored. An unknown error occurred (48). I have kept on repeating the steps over and over and over again for hours. What do I do?? I don't want to buy a new phone but I don't want this problem to stay here. So what now?