Ring Doorbell Pro not activated by plug-in Adapter (2nd Gen)

Ring Pro worked perfectly for over a year, wired to old, recessed doorbell chimes.
Then, steady, low buzzing within chimes started 2 months ago. Call with Ring tech support confirmed that they have seen this happen many times. I disconnected Ring from old wiring, and connected by 2nd Gen plug-in Adapter. Does not light up at all, despite clear evidence that outlet is working. I fear the Ring Pro may have been damaged in the buzzing fiasco.
Key Q: Is there an independent way to assess whether the Ring Pro is toast, or just needs some other TLC to work? Can I take it or send it somewhere?

Hi @Johnrhaig. If your Ring Pro 2 is not lighting up, that is indication that there may be a failure in the device. I suggest reaching back out to our support team to see what your options are. Please give our support team a call at one of the numbers available here.