This time something different that's not related to Commodores.
One shiny day my Intel Mac Pro simply decided not wanting to boot anymore. It powered on but didn't give the boot chime or show anything on the display.
It only spun the hard drive and toggled fan speeds just like it was executing the boot procedure. After some seconds the fans got louder and then quieter again.
Obviously the machine was in some kind of boot loop. The day was not so shiny anymore.
The previous day the computer ran fine so what broke it suddenly, I don't know.
Maybe this is another Apple feature, who knows.
I opened the case and pushed the diagnostics button to see what the computer was doing during the boot.
All the leds got lit in a sequence but when the EFI led got lit the computer rebooted itself.
Apparently the problem was with the EFI code. EFI is like the BIOS in the older PCs, without a working BIOS the machine is dead weight.
I did all the basic steps trying to troubleshoot the situation:
Probably the EFI firmware was corrupted somehow but how to fix this. A couple choices came to my mind:
I took the logic board apart from the case, masked the neighbour parts with foil and kapton tape and desoldered the chip using a hot air gun.
Then I plugged the chip to my good old eprommer and downloaded the Mac Pro firmware from the Apple's website.
I dumped the corrupted EFI firmware and compared it against the downloaded firmware. Yep, they weren't exactly equal.
Out with the old and in with the new. The EFI chip was flashed with a new firmware.
After programming the chip was soldered back to the logic board and the Mac was reassembled for a test run.
I turned the Mac on and this time got the boot chime which was a good sign. The Mac booted to OS X as if nothing had happened.
Another Mac unbricked.
One shiny day my Intel Mac Pro simply decided not wanting to boot anymore. It powered on but didn't give the boot chime or show anything on the display.
It only spun the hard drive and toggled fan speeds just like it was executing the boot procedure. After some seconds the fans got louder and then quieter again.
Obviously the machine was in some kind of boot loop. The day was not so shiny anymore.
The previous day the computer ran fine so what broke it suddenly, I don't know.
Maybe this is another Apple feature, who knows.
I opened the case and pushed the diagnostics button to see what the computer was doing during the boot.
All the leds got lit in a sequence but when the EFI led got lit the computer rebooted itself.
Apparently the problem was with the EFI code. EFI is like the BIOS in the older PCs, without a working BIOS the machine is dead weight.
I did all the basic steps trying to troubleshoot the situation:
- Tried to reset the NVRAM and PRAM settings.
- Reassembled whole computer if some component had a bad connection. Also tried the memory modules in different slots.
- Tried to boot without the GPU card.
- Removed the hard drive in case the system partition was faulty but that didn't help either.
- Tried to get it to the firmware recovery mode by keeping the power button down. It began to blink the power led rapidly but didn't open the DVD tray as it should have been. Instead it just rebooted itself again.
Probably the EFI firmware was corrupted somehow but how to fix this. A couple choices came to my mind:
- Send it to the AppleCare for repair. Very expensive as the warranty is already expired and I guess they only would have replaced the motherboard, I mean the logic board. And probably scratched the mint case in the process.
- Buy another logic board but that's also pretty expensive.
- Use the Mac as a boat anchor and forget about it. Quite tempting thought actually...
- Repair the Mac by reflashing the EFI chip.
I took the logic board apart from the case, masked the neighbour parts with foil and kapton tape and desoldered the chip using a hot air gun.
Then I plugged the chip to my good old eprommer and downloaded the Mac Pro firmware from the Apple's website.
I dumped the corrupted EFI firmware and compared it against the downloaded firmware. Yep, they weren't exactly equal.
Out with the old and in with the new. The EFI chip was flashed with a new firmware.
After programming the chip was soldered back to the logic board and the Mac was reassembled for a test run.
I turned the Mac on and this time got the boot chime which was a good sign. The Mac booted to OS X as if nothing had happened.
Another Mac unbricked.
