I have a Sony E-Reader Pocket edition. It’s an old model, silver with no touch screen or color. Before, it would start to turn on, but shut down before it would finish loading. Now the light by the power switch flashes yellow, with no other reaction when I try to turn the reader on. I know it’s charged because it was on the charger all day yesterday and last night as well. Plus, it was working fine until this morning. How to fix a Sony E-reader Pocket edition that is not turning on? Thanks.