My phone died from no battery a week or two ago, and since then I haven't been able to charge it or turn it on. When I plug the phone into a charger it flashes red (also flashes red when the battery is not in there). What does the red flash mean? This has happened before but never for this long. I found out you can replace batteries so I'm going to try that, but if I change the battery will the stuff on my phone go?