Ring Pro doorbell died after 3.5 years

After 44 months of faithful service, my Ring Pro doorbell--installed Jan of 2018--spontaneously gave up the ghost. I spent a number of hours trying to troubleshoot the issue...at first replaced the transformer (because I had to do that when I installed it originally; seemed most likely to be the problem). That didn't solve it. An hour on the phone with Ring tech support (40 mins on hold, to be clear) ended with the recommendation to call an electrician. Called two electricians I trust; neither was willing to work on doorbells; not sure why...On a whim, took my voltmeter to the hardware store and turns out the problem was with the voltmeter. So all those times I was trying to test power at the doorbell and thinking it wasn't working, it was.Not sure how I feel about getting less than 4 years out of the product. Works out to about $50/year, which--while I like the product--isn't chump change.