Diagnostics: Macs Made Since Mid 2014

To diagnose machines that are newer than 2014 run AST2 through GSX. Apple Service Toolkit 2 (AST 2) is a cloud-based diagnostic system to help technicians triage and verify repairs for Mac Computers. AST 2 supports iMac (21.5-inch, Mid 2014), MacBook Pro (Mid 2014)all Late 2014 Mac Computers, and any subsequently released Mac Computers.

Follow these instructions to run both the Mac Resource Inspector (MRI) and the Storage Diagnostics (SD) tests. 

Please first refer to the Diagnostics Procedure before following these steps.

Open GSX

In GSX, enter an eligible device serial number and click the Request Diagnostics button at the top of the screen.


Now in AST 2

Diagnostic Console Opens

AST 2 loads on the Diagnostic Console (Mac). On the Diagnostic Console, enter the customer-reported symptom or pick a symptom from the pop-up menu as you type. You may see a list of devices in the sidebar if you are testing other devices or if other devices have been tested. Tap the right arrow next to the symptom description to proceed.

Start up customer's device

At this point, start up the customer’s device while holding down Option-D

Note: If you do not enroll the device in the Diagnostic Console within the first few minutes, the device will start running Apple Diagnostics.

Important Tips for Desktop Devices:

  • Connect a known-good wired Apple USB keyboard and a known-good wired Apple USB mouse to any available USB ports on the device.
  • Do not use a third-party USB keyboard or mouse with either version of AST. Third-party devices may require drivers that would be unavailable in the EFI environment and may cause AST to stop responding.
  • If the device stops responding while starting AST 2, press the device’s power button for 10 seconds to shut down, then retry.

Obtain customer's permission and check the device

The device connects to the AST 2 cloud-based server and loads the Informed Consent dialog within several seconds. Obtain the customer’s permission to proceed with the diagnostic. Explain that only the hardware diagnostic data and Computer serial number are collected; no personal information is collected.

If the customer agrees to send this information, click “I agree” to proceed. If the customer does not agree to send the hardware diagnostic data and Computer serial number to Apple, press Escape or click “Run offline” to proceed. Apple Diagnostics will run on the device as shown in the next image.

Apple Diagnostics will check the Mac

Apple Diagnostics will check the Mac

If an issue is found, Apple Diagnostics produces an error code. The error code, along with a description, gives the customer more information about the issue. 

For more information on Apple Diagnostics, refer to articles HT202731: Using Apple Diagnostics and PH21879: Use Apple Diagnostics or Apple Hardware Test.

The colored bars next to the device in the Diagnostic Console indicate the following:

A blue bar indicates that a device is currently online and ready for diagnostics.

A pulsing blue bar indicates two things:

  1. The device or Diagnostic Console may need the technician’s attention. For example, it may be running an interactive diagnostic like Display Anomalies, where the technician must view the device’s screen and answer a question on the Diagnostic Console before the diagnostic can proceed on to the next step.
  2. The technician has not yet viewed the device's diagnostic result.

A gray striped bar indicates that the device is no longer connected to the Diagnostic Console. To remove the device from the list, click or tap on the device under test and then tap on the archive icon (file cabinet) to archive the results.

If the device is not showing as blue (online) in the sidebar:

  • Network disconnection: Check network connections, such as the Wi-Fi or the Ethernet cable. The device could also have a network issue as part of its overall issues. Try another network interface (if using wired Ethernet, try Wi-Fi; if using Wi-Fi, try wired Ethernet). Also check that Internet access is not blocked by firewalls or proxy.
  • If the device is not connecting to the Diagnostic Console, restart the device while holding down Option-D. Also, if using Wi-Fi, note that the device must join the correct Wi-Fi network during EFI startup.

Select and Run Diagnostics

AST 2 Diagnostic Suites load to the Diagnostic Console, allowing you to select which diagnostics to run. A complete list of diagnostics that are appropriate for that device will appear.

Icons on the Diagnostic Suites screen:
i = Click or tap the info button (i) for a description or more information about the test suite.
> = Click or tap the arrow button (>) to begin a diagnostic test.


When you click or tap the arrow button (>), the selected diagnostic is pushed to the device and the test information is displayed on the Diagnostic Console. In the graphic below, Mac Resource Inspector (MRI) was selected and is running on the device under test. The blue progress bar indicates the time remaining to complete the diagnostic.


View Test Results

When the diagnostic is finished, the technician view is displayed in the Diagnostic Console. Click or tap the Info button (i) next to Testing Complete to bring up the customer-shareable diagnostic results (see next step). The graphic below shows the MRI results.

Note: The test results are sent to Global Diagnostic Exchange (GDX) after each test suite completes. GDX results populate within GSX.


Share the test results with the customer. Result status can be quickly identified by the following badge icons:

  • Green check mark = Test passed
  • Yellow question mark = Test requires technician attention
  • Red exclamation mark = Test failed, device requires further attention or diagnosis

Click or tap on each icon for detailed test results. Depending on the MRI diagnostic results, you may want to continue with other test suites. Otherwise, after reviewing the diagnostic results with the customer, you can archive the device’s test results.

Running diagnostics with no video

AST 2 Diagnostics: If the device has no video, the following sequence can be taken to run AST 2 Diagnostics. AST 2 will not proceed beyond the Informed Consent dialog automatically.

Press the Return key to default to English on the language select screen, then press the Return key again to agree to the Informed Consent dialog. The device will wait for instructions from the AST 2 Diagnostic Console.

Apple Diagnostics: If the customer does not agree to send hardware diagnostic data and Computer serial number to Apple, the following sequence can be taken to run Apple Diagnostics:

  • Press the Return key to default to English on the language select screen, then press Escape to decline the Informed Consent dialog. The device will run offline Apple Diagnostics.

Once diagnostic tests are complete, the device can be shut down or restarted by the following sequence:

  • Shut Down: Press S, then press the Return key.
  • Restart: Press R, then press the Return key.

Seek advice from a technician if there are other tests offered and it is unclear whether they should be run. These tests should only be run by employees who are trained and authorized in this aspect of GSX.

Please remember to document all test results in the SRO.