Respuesta a "Is it possible to diagnose a bad power supply in an iMac Pro?"FYI: I had the same exact thing happen to my iMac Pro on the 8th of May. It just stopped working. No power. No hum. Nadda. Ziltch. Took it in to the Apple Store and they fixed it with a “hard software reset” which, it seems, included the EFI firmware and OS. Oddly, the cost was $0. Sounded odd to me. A firmware update gone bad?