No light on charger when plugged in

Have any of you guys ever had a SP4 not light up when charger plugged in? It will not come on. Charger works with another unit. I’m trying to see if I should go after the charge port, or battery. Is it the connection, ie-charge port, or possibly not recognizing the battery? I have both parts coming, but was just checking to see if any of you guys have ever ran across this. MS suggested on a couple of threads to replace the charger. These work! Just not with this particular device at the moment