I have a new sa4315/97

Question

I have a new sa4315/97 which was set up last night, transferred files ok and worked well. Plugged it into the computer this morning and the device manager couldn't find it and to run the repair option. Did that and now the player will only power up for long enough to tell you that there is a problem. Have tried a number of times to repair and have uninstalled and reinstalled software, all to no avail. Help......