It is a condition that every computer user dreads: the display remains dark, the keyboard and trackpad do not respond. In this condition, error diagnosis is difficult because the computer cannot provide the user with any information about existing problems. For Apple computers from MacBook to iMac to Mac Studio and Pro, the blog “The Eclectic Light Company” recommends a procedure to determine the cause of the computer coma. Portable Macs clearly indicate their general functioning via an LED in the MagSafe charging cable. The power supply is an important but often overlooked source of error: First check whether the power supply can be restored by changing the power supply. First, plug the plug into another socket, preferably one directly in the wall. A USB-C charging adapter with at least 65 W maximum power helps to eliminate this cause of error in Apple laptops. The same applies to desktop models such as Mac mini, Mac Studio and (to some extent) iMacs: it is rare for a power cable to break, but not impossible. Thanks to the C7 socket on Mac mini and Mac Studio, there is a cheap replacement; The iMac’s power cable can be replaced with a standard Type-F cable.
Helpful status light
The next big challenge is figuring out whether the Mac has a hardware problem or is stuck in DFU mode. Apple’s desktop devices without their own monitor have an integrated light that makes diagnosis noticeably easier: the status light (Status Indicator Light, or SIL for short). If your Mac has a firmware problem, this light on the front will turn orange instead of white, or blink orange. If it flashes white, there is a hardware problem.
Restore Mac in DFU Mode
Unfortunately, portable Macs lack this light, which makes diagnosis difficult: With a MacBook in DFU mode, not even the LED in the MagSafe cable lights up. In this case, it’s best to assume that your MacBook (Air or Pro) is stuck in DFU mode. To fix this, you need a second Mac and a USB-C data cable. Important: This must not be Thunderbolt compatible, otherwise it will not work. Plug this into the DFU port on the unresponsive Mac and connect it to a USB-C port on the other Mac. You can then reset the firmware of the defective Mac on the working computer.
DFU connector location
| Device | Device page | position |
| iMac | rear | right |
| Mac Studio | rear | right |
| Mac Pro | above | right |
| Mac mini | rear | T2: right; M1-M2: left; M4: Middle |
| MacBook Air | left | T2: right; M1-M3: left, M4: right |
| MacBook Pro | left | T2, M4, M5: right; M1-M3, M4 Pro & Max: left |
Other problems
A flashing white status light or a MacBook that is still unresponsive usually means a hardware defect that the user cannot fix (or even diagnose) themselves. In such a case, Howard Oakley recommends visiting an Apple-authorized support center – if a normal restart fails, the Mac is unlikely to boot into recovery mode.
