I was messing around with one of my bikes last night and disconnected my CA and when I reconnected it the screen came on but was blank so I let it sit over night and it is still blank. Have you ever saw this kind action?
if it's an older CA, v2.x, there were some that got the wrong transistor for the voltage regulator, and when run high enough in voltage could pop. Contact info@ebikes.ca and they can help with it if it's that.