"Unable to read memory card"に関する回答It could be that your phone does not support a memory card of the size you are using. It could be that the reader is dirty, and needs to be cleaned or replaced.
"Keyboard and power button not working"に関する回答You should go to someone, and repair the wire. It might be the reason! Update (02/19/2019): It also could have been the fact that something spilled on the keyboard, but probably the components and wiring. There is also the fact that it is to old to survive!