Mac mini 2012 2.3 i7 server repeating boot chime

[MiBook84]

Hello, my 2012 server i7 2.3 dual 1TB mac mini has been acting up. First one of the drives failed according to it. But outside of the machine both drives seems fine. After replacing the drives it didn't turn on properly and not just leaves me with a repeating boot chime. Different drives or ram does not make any difference.

Resetting SMC does nothing. Resetting PRAM seems not even possible because the keyboard isn't lighting up at all. I also noticed that an external hard drive would spin up but its light would not turn on, which it does on any other computer.

I wonder if the issue might be PSU-related, like it isn't giving enough power on 12/5V or something like that. I have disassembled it entirely again and looked closely at the boards and I can not see any damage or whatsoever that might have caused any error.

It's a cute and great machine so it would be nice to have it up and running again but for now I guess it might not happen. If anyone has any advice I'm happy to try it.

But, since it can not boot past the boot chime - I can not reinstall an operating system, boot from USB or any other kind of device. It simply seems stuck there. To be noted too: it also boots automatically without a push of the power button. I have removed the battery for over 30 minutes without any different behaviour as well.

Thanks!

 

[Kaida]

The power button is stuck shorted. That's why it turns on once plugged in and off right after 4 secs, and on and repeat. try to loosen it up or unplug the power button. Then use a test pen to short to try to turn it on. Hope it helps!

 

[MiBook84]

The power button is stuck shorted. That's why it turns on once plugged in and off right after 4 secs, and on and repeat. try to loosen it up or unplug the power button. Then use a test pen to short to try to turn it on. Hope it helps!

Unfortunately this was not the case. I just tried holding down the power button and it would then turn off and stop trying to boot. Pulling the plug and putting it back in would leave it off, and pressing the power button again would start the boot loop chime-thing again. So I guess the computer is acting properly, keeping the last state it was in when power is back.

I see that there is companies that offer boards with "external" Efi chips on them, which has helped people with accidental broken EFI data (when people been trying to install clover efi on real Macs). I don't know but I see it as possible that the EFI chip on my Mac mini is damaged somehow and putting it in this loop. I am considering buying into this option but since I can't rule out anything else yet, I think maybe I should wait. I also don't want to do anything to make it worse.
I still believe maybe the power supply is the issue. Or is perhaps USB power initiated post boot chime process? I can't even get a red light from an old Apple USB Mighty mouse. (update: I do get red light from the mouse if I connect it directly to the mac, not via keyboard).

 

[Santabean2000]

My 2011 mini differed the same fate. Ultimately it was diagnosed as a failed logic board.

Dead.