How to Use Apple Diagnostics to Troubleshoot Macs

This step-by-step guide explains how to use Apple diagnostics to troubleshoot macs. It covers the required setup, the main actions, and the checks that help prevent common problems.

It is common for a computer to crash. Some errors, especially hardware-related errors, emit signals can be detected by computer programs and reveal the cause of the problem. Diagnostic programs that can perform this process are usually only available at authorized stores. However, you can use Apple Diagnostics to access Apple's diagnostic package from any Mac.

Apple Diagnostics is a diagnostic tool built into every Mac. Apple Diagnostics can run diagnostic algorithms on Mac hardware without accessing the Apple Store. You can use Apple Diagnostics to find problems in all major Mac systems, from input devices such as keyboards and touchpads to display devices such as graphics processors, then CPUs. , memory, etc. . Although it is only possible to find the problem programmed to detect and the analysis is nothing special, but Apple Diagnostics can tell about the severity and type of problem. That you encountered.

Apple Diagnostics must be run immediately after booting and requires restarting the Mac. This tool will help if you disconnect all unnecessary peripherals first and only connect the keyboard and mouse. This reduces the number of confounding factors, which can make the diagnostic process complicated.

1. Disconnect all peripheral devices from the Mac, except for the mouse and keyboard.

2. Turn off the Mac.

3. Restart the Mac and hold the D Key on the keyboard.

4. Wait a few minutes for Apple Diagnostics to finish running. After finishing, you will see the relevant diagnostic reference codes appear on the screen.

5. After the test is finished, you can repeat the process again, find more information about the error code or turn off and restart the Mac normally.

If you find a problem, it's best to repeat the test. If you don't see the problem appearing during the test run again, it could be a 'fake' error. If you get the same results after many tests, you will be more certain about the cause of the problem.

If you receive a battery-related error code (PPT004), Apple strongly recommends that you run Apple Diagnostics over the Internet. To do this, turn off your Mac as usual. After that, turn on the device and hold Option + D Instead of just D Key as in the previous section.

The reference code consists of 3 letters, followed by 3 digits without spaces. As follows:

CNW001-006: The problem was detected with Wi-Fi hardware
CNW007-008: No Wi-Fi network found
NDC001-006: There is a problem with the camera
NDD001: There is a problem with the USB controller
NDK001-004: There is a problem with the keyboard
NDL001: There is a problem with the Bluetooth hardware
NDR001-004: There is a problem with the trackpad (touchpad)
NDT001-006: There is a problem with Thunderbolt controller
NNN001: The serial number cannot be detected
PFM001-007: There is a problem with the System Management Controller (SMC) - System management controller. This chip handles low-end hardware control on modern Macs.
PFR001: There is a problem with the computer firmware
PPF001-004: There is a problem with the fan part
PPM001-015: There is a problem with internal memory
PPP001-003: There is a problem with the charger
PPP007: Charger is not tested
PPR001: There is a problem with the CPU
PPT001: No battery detected
PPT002-003: 'Health' of the battery is very weak
PPT004: Battery requires service
PPT005: Incorrect Battery installation
PPT006: Battery requires service
PPT007: Battery replacement required
VDC001-007: There is a problem with the SD card reader
VDH002-004: There is a problem with the internal storage device
VDH005: Could not start from recovery partition
VFD001-005: There is a problem with the screen
VFD006: There is a problem with the graphics processor
VFD007: There is a problem with the screen
VFF001: There is a problem with the audio hardware

Basically, in all cases (except ADP000 ), Macs often require some kind of service. The specific details of the service are not specified by the diagnostic program, but the reference code is a useful first step for technicians responsible for resolving problems on a Mac.