Dear friend,I don't have a multimeter but the adapter works fine. I've tested it by using the K5 Pro adapter on a Philips lamp and the lamp powers up.
Using the adapter of the lamp does not power up the K5 Pro so it is the probably the K5 Pro itself that is broken.
Sorry to hear about that. According to the phenomenon you metioned, I am afraid that it may be a hardware issue with the K5Pro as well. You could try to contact the seller for help first. If the seller fails to help, please contact email@example.com with the receipt attached.