First, try resetting it. Hold the sliding power switch on the side in its uppermost position for 20-30 seconds. If at first you don’t succeed, try again for longer. This may or may not help, but doesn’t cost anything but a minute or 2 to try it.
If it’s still DOA, then most likely it’s defective. I doubt whether anything else you can do will revive it. There are a couple of procedures like formatting and re-loading firmware that can be done, but based on what you’ve described, I think it would be a waste of time. Best to call SanDisk Support. They may have you do these procedures anyway just in case, and so they can verify that everything that can be done has been done, but in the end they can set you up with an RMA to get it replaced for you if it’s still unresponsive and under waranty.