I recently acquired a free 2014 iMac with a faulty motherboard, but the screen worked fine. I’ve seen a few people convert them into what is basically just a Apple Studio Display. These screens are 60Hz 5120x2880, and look amazing so for a second monitor/graphics monitor it’s perfect.

You basically have to remove everything from the iMac housing, motherboard, power supply, hard drive, and replace it with a display driver board, speaker crossboard (if you want speakers), fan controller (if you want a fan), and 12v or 24v power supply.

There’s a few repos I found with different ways to mount all of this hardware, but none that I found were complete, and some were just wrong.

So I decided to use the good models I found with slight modifications, mostly just to reduce the excessive amount of filament they were using and just fix the broken models. I did this to try and make the most complete set of parts required to convert one of these monitors.

The electronics needed for this conversion are as below -
StoneTaskin JRY-W9CUHD-AA1 - This part can vary based on your model of display, so check that.
MEAN WELL LRS-150-12
Speaker Crossover Filter
Fan Controller with Temp Sensor

I did do some modications to my parts, I cut the power button off of the supplied board as I just wired in the original iMac power button to serve that function, this allowed me to print my RAM cover which built in buttons and DisplayPort/USB C ports for a much cleaner look. I wired in the original iMac power plug to power the Meanwell power supply.

Here’s the repo below.

iMac 27” (2014-2019, Intel) A1419 Conversion to External 5K Monitor

On the left, the iMac in it's current state with the 3D printed mounts installed. On the right, the rear panel for the monitor controls and display ports.