## patch-edid.rb

A script to fix EDID problems on external monitors in Mac OS.

### Additional reading

* [The original forum thread](http://embdev.net/topic/284710)
* An improved version of the script [by adaugherity](https://gist.github.com/adaugherity/7435890)
* [An explaination of the problem](https://spin.atomicobject.com/2018/08/24/macbook-pro-external-monitor-display-problem/) from Atomic Object's blog

### Instructions

⚠️ **This requires disabling SIP, so run this at your own risk. Be sure to re-enable SIP at the end.**

1. Disable [System Integrity Protection](https://support.apple.com/en-us/HT204899) while in [Recovery Mode](https://support.apple.com/en-us/HT201314). Reboot back into macOS when done.

    ```
    csrutil disable
    ```

1. For macOS Catalina and newer (which uses a [read-only system volume](https://support.apple.com/en-us/HT210650)), mount the system drive read/write (yes, this is in addition to disabling SIP)

    ```
    sudo mount -uw /
    ```

1. Connect *only* the problem monitor

1. Download this script in the directory containing all the display override plist files (note: even with the steps above, this command requires sudo to run):

    ```
    cd /System/Library/Displays/Contents/Resources/Overrides
    sudo curl -O https://gist.github.com/ejdyksen/8302862/raw/patch-edid.rb
    ```

    You may also want to use [adaugherity's version](https://gist.github.com/adaugherity/7435890) of the script:

    ```
    cd /System/Library/Displays/Contents/Resources/Overrides
    sudo curl -O https://gist.github.com/adaugherity/7435890/raw/patch-edid.rb
    ```

1. Run the script we just downloaded (as root again). This creates a new display override plist.

    ```
    sudo ruby patch-edid.rb
    ```

1. Reboot into recovery mode to re-enable SIP.

    ```
    csrutil enable
    ```