How to tell if my led strip is busted?
Was it very bright, once, and now it doesn't light?  That was you frying it.  

LED strips do not have switching regulators on them, current limiting is done by dumb resistors.  They are running at absolute limits on 13.8V which is float voltage for an automotive alternator.    

Looks like you're out $22.  Sorry.  

Now if you really need to run off 19v, you can buy a type of LED strip designed to run on 24V.  Those will be notably dim, but it's worth a try.