iMac M1 to external display conversion?

[uller6]

Before I do anything silly, I thought I would seek out the wisdom of MacRumors community for feedback. I'm wondering if its possible to convert an M1 iMac (and that gorgeous 4.5K screen) into an external display, similar to how some others have converted both 27" and 21.5" iMacs into external displays using third party control boards and power supplies. iCloud locked M1 iMacs can already be had for $500-$600 on eBay. I think it might be possible to cut a small hole in the back of the chassis, run the LVDS cable from the screen to an external control board/power supply, then mount that control board on the back of the iMac. The additional hardware may not fit internally but at least I wouldn't be able to see anything from the front.

Does anyone know what the pinout diagram of the LVDS cable in the iMac is, and if that cable could be used with an external driver board? Then, which control board on the market that would work with the M1 4.5K display? Would a board meant for a 5K display work fine, or does it need to be for a 4.5K That's tough, because there aren't any more 4.5K displays on the market as far as I know.

I would love to have a matching external display next to my M1 iMac, but is this just an exercise in stupidity?

 

[Basic75]

iCloud locked M1 iMacs can already be had for $500-$600 on eBay

Stolen? Or why else are they locked?

 

[uller6]

Stolen? Or why else are they locked?

Or returns with the AppleID still on the machine. I haven’t purchased one I was just trying to illustrate the current price point of non-functional M1 iMacs.

 

[uller6]

I'm digging up my own post again to ask if anyone knows of 4.5k drive boards for iMac M1/M3 screens! You can now buy separate 4.5k display assemblies from Alibaba or eBay, so if a drive board exists I would love to turn one of these amazing displays into an external monitor!

 

[meson]

Why not just buy a used M1 iMac and use it via Universal Control? You can set up the second machine to act as an extended display.

For a year or so I ran a 2013 iMac with UC enabled by OCLP. It worked very well. I had a couple issues due to the older hardware, but it works much better on two M series machines.

I get the idea of wanting to salvage a locked device, but spending $500-$600 on a machine plus a couple hundred in parts puts the price on par with a discounted new base model machine at Best Buy, Woot, or other retailers. If it’s for the novelty, experience reverse engineering, etc. it is an interesting project and good luck.

 

[PaulD-UK]

I guess the hardware for a LCD video driver board already exists - an R1811 or similar. Probably its a matter of firmware to provide the 4.5K timings - and a suitable eDP and backlight cable to match the panel.
Once enough of panels are available on the Chinese electronic market there will be people to write the firmware to 'test' them.

 

[uller6]

If it’s for the novelty, experience reverse engineering, etc. it is an interesting project and good luck.

You hit the nail on the head here...

 

[WhiskeyJan]

Why not just buy a used M1 iMac and use it via Universal Control? You can set up the second machine to act as an extended display.

For a year or so I ran a 2013 iMac with UC enabled by OCLP. It worked very well. I had a couple issues due to the older hardware, but it works much better on two M series machines.

I get the idea of wanting to salvage a locked device, but spending $500-$600 on a machine plus a couple hundred in parts puts the price on par with a discounted new base model machine at Best Buy, Woot, or other retailers. If it’s for the novelty, experience reverse engineering, etc. it is an interesting project and good luck.

In my experience, I had to buy an iMac with 8 GB memory because I needed a computer then and there. The 8 gig model was the only one they had at the store.
Now, two years later, this thing is running out of memory with office work. When the SSD dies, Universal control will not help, while the screen will still be amazing. I really hope that someone will come up with a driver board until then..