Since experiencing a voltage spike, my iMac A1419 won't fully boot up. I get normal chime, apple logo, and boot sequence until just past midway in the progress bar, then it shuts down.
I have unplugged all peripherals, attempted SMC reset multiple times, zapped pram, attempted to boot in safe mode, recovery mode and from a flash drive. Same partial boot and shut down in every case. No unusual sounds.