My Apple Watch series 1 42MM does not have a serial number etched anywhere on it, I don’t have my original box it came in and it won’t power on

My daughters Apple Watch series 1 does not have a serial number etched in it and it does not power on. It will show Apple icon when you do the hard reset then goes black again. I have an original charger but it does not show charging icon when put on the charger. Not sure what I can do to fix. Any ideas?