Won't Charge, Won't Turn On, But Trying to Retireve Data

A couple of years ago, my grandmother turned her RealPad over to me to "fix". Apparently, it wasn't charging or turning on. This wouldn't be a problem, if it didn't have a picture saved to it that she desperately wants. My first stop was AARP's website to try the Customer Service route, but it looks like that's no longer available. So far, I have tried cleaning the charging port, using a newer charge cable, and plugging said cable into a wall outlet as opposed to a USB port on a computer. No dice. I lack the know-how and tools to be able to tell if the battery is dead, or if it's a much bigger problem. Does anyone have any advice on how to either 1.) diagnose the problem with more accuracy, 2.) retrieve the data off of the tablet without repairing it, and/or 3.) locate a replacement battery for the retched thing?