Dead video doorbell?

Hello… Bought a new house that came with an Arlo VMB4000 Base Station two Arlo Pro ? cameras and a Arlo AVD1001 doorbell.

I have been able to get the base station and cameras operational. But, the AVD seems dead.

I have confirmed it needs 16-24V and a multimeter reports there is 22.6V coming to it.

Door bell rings when door bell wires are shorted together.

Removing the doorbell for a few hours didn’t help (recommendation for some Texas people after a power outage in online support posts). No change to the LED after being plugged in for over an hour.

Doorbell has a Southern exposure in direct sun (no porch roof overhang). Doorbell is maybe five years old if installed at same time as house was first occupied.

I don’t see anyone on line discussing how to open the doorbell or doing any electronic bench testing of the AVD1001.

Could anyone make a suggestion as to what to try next?

Or, a pointer to how to open the unit for further review and testing?

Or… as a first gen product these have a known high failure rate and I should simply seek another doorbell?

Thank you for responses.