My iPhone 3GS (32 gb) randomly turned off last night and now it won't turn back on. I know it was at least 70% charged the last time I used it, but I wasn't using it when it randomly turned off.

I tried to charge it with my wall adapter, car adapter, and I tried hooking it up with USB to my laptop and nothing has worked.

Do you think this a battery issue since it doesn't even show a "charging" symbol when I plug it in? It is an older phone and I've never replaced any parts on it.

I want to avoid having to restore since I will lose all my data and photos (which wasn't properly backed up the last time I connected to iTunes). :( Please help!