My brother's iMac was stuck in a boot loop (starting, restarting, going white, repeat), and so we started Internet Recovery, which is seemingly stuck at 24:00. Prior to this, the iMac had been experiencing some issues with simple tasks, like hovering over the dock, causing it to flicker and go white. We are not exactly sure what model the mac is, but it looks like a 2017 era iMac (It is older, though, as the latest macOS it can run is High Sierra)
Earlier Mac models
It has likely suffered a hardware failure. Please follow the steps in If your Mac doesn't start up all the way - Apple Support
If you exhaust all the steps it is time to take it in for service to be professionally diagnosed, if it is a hardware failure then you can decide what to do. Please only take it to an Apple Authorized Service Provider not your local PC shop as a PC shop does not have the training or the tools available to them. If you don't know of an Apple Authorized Service Provider in your area please click Apple Authorized Service Provider Locator (AASP) & Genius Appointment
Good luck!
It has likely suffered a hardware failure. Please follow the steps in If your Mac doesn't start up all the way - Apple Support
If you exhaust all the steps it is time to take it in for service to be professionally diagnosed, if it is a hardware failure then you can decide what to do. Please only take it to an Apple Authorized Service Provider not your local PC shop as a PC shop does not have the training or the tools available to them. If you don't know of an Apple Authorized Service Provider in your area please click Apple Authorized Service Provider Locator (AASP) & Genius Appointment
Good luck!
iMac stuck in boot loop
