Instructions for Forcing RGB mode in Catalina

forcergdb.txt

https://www.reddit.com/r/MacOS/comments/dkowz1/instructions_for_forcing_rgb_mode_in_catalina


Instructions for Forcing RGB mode in Catalina
This is basically a copy/paste from an Apple discussion thread, but there is one important step not mentioned in the thread. The original thread can be found here. You do not need to disable SIP for this. The monitor you want to use should be connected during this process.



Download this script: https://gist.github.com/adaugherity/7435890

Place the patch-edid.rb file into the /Users/ directory

Run this command in Terminal: ruby /Users/patch-edid.rb

Take note of the DisplayProductID and DisplayVendorID file names. These will vary based on your monitor.

Move the output file named "DisplayProductID-XXXX" from /Users/~username/ to the /Users/ directory

Reboot your Mac in Recovery Mode by pressing Command+R as soon as you see the Apple logo after rebooting

Open Disk Utility in Recover Mode

Check to see if "Macintosh HD" is mounted. If it isn't you will need to mount it before proceeding.

Exit Disk Utility

Open Terminal in Recovery Mode

Run this command in Terminal (make sure to include spaces):

cp /Volumes/Macintosh\ HD/Users/DisplayProductID-XXXX /Volumes/Macintosh\ HD/System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-XXXX

12. Restart computer and the monitor should now be in RGB mode.



I hope this helps anyone whose monitor stopped working properly after the Catalina update.