Check the power supply voltage with a volt meter without & with the charger connected & when you try to start the charger.



Connect it to a car battery & try it.


If it works with the battery & not the power supply, then there is a problem with the supply. If it does not work on the car battery it is likely the charger.

Now it could be a bad connection, plugs go bad. Any of them can. It could also be the battery, not likely but possible.

Hopefully it is something simple.

Tom