Yes! Like for the mac power cables themselves, does it matter which one connects to 4 and to 7? Also, connecting to 3 instead of 7 should work as well?
Got it! And when connecting the wires, I just have to make sure it's connected to the controller strip, not the r1811 board as well? Or should I splice the wire instead?
Got it! I'll probs do a three way splice, I dont think that should mess up anything?
Sorry for another follow-up! Would splicing in either of these ways be okay? Or would one be preferable? Thanks!
Soldering is no problem for me! Im most concerned about which connections need to remain. Like does there have to be a connection to the R1811, or is just the controller strip to the imac power cables good enough? Or from the r1811 board to the power cables, or all 3?
The two wires from the iMac's power button should touch the two points on the R1811 board that corresponds to the power button.
Thank you to everyone for the help! My rig is finally complete! This was my first DIY project, so I was bit nervous but still excited to dive in. Using Gold's setup as inspiration, I ended up installing an 8-speaker system as well, with a temperature control system. Just wanted to give some of my thoughts and add some other tips and perspective.
For the iMac cables, I ended up soldering to the back of the power switch. The pins at the cable portion were so close together that it made sense to use the pins that were more spaced out. I verified with a multimeter that the positive side has continuity with the power (pin 4), and the negative with the ground (pin 3).
So that one cable that connects between the R1811 and LP0818 is enough to facilitate the connection between the two, and the difference is honestly night and day. Then I just used the installed backlight cable on the r1811 to connect to the display.Hi, thanks for all the pics. Nice information
A couple of points:
How is you screen Backlight connected? It still seems (in the pic) that the cable to the backlight for the screen is connected/powered by the R1811 board, while the LP0818 board seems to have nothing connected to its outputs (only the input from the R1811).
And does the Noctua fan have a cool air inlet in the rear of the case?
Ohhh I see now! I uploaded an older photo. I connected the two connectors from the cable that connects to the display (with the pointed pins) to each connector on the other side. It’s still controlled by the strip yeah
Hi, I got same Jst connector but still cant understand how to connect to 2 speakers 4 pins to this single 4 pin connector. Board speaker socket notes L+, L-, R-, R+ does this imply we need to connect left speaker pins to L+, L- on board. This conradicts Y shaped connector to connect left, right speaker pin to board pin. Also. on imac speaker, I cant find which one is pin 1 as they look identical. Thanks much
On board 4 pin socket notes, L+, L-, R-, R+ . Does this imply left, right speaker connection. If so this implies, A1+C1 goes to W not A1+A1 to W. what am I missing. Thanks muchSome comments on your post:
I guess used 2020 iMacs are still more expensive than older ones and in terms of the screen there is not much difference (2014 – first 5k, 2015 – first with P3 support). Also 2020 iMacs wern’t a good deal back them since they were not as upgradable as previous models.
1) Safety – I personally use a Thunderbolt dock inbetween the screen and the laptop. Makes it a bit more expensive but you might feel more safe. Alternatively you could go with an adapter that merges two DPs into a USB-C. That would be a middle link to feel more safe.
2) Noise – honestly, I’m totally fine with the default fan (I use R1811). I actually tried Noctua fan featured in this thread but to me it was more loud (not much but tiny bit).
3) Brightness – 5k panels of 2014 and 2015 don’t require another converter, every panel after 2015 including 2020 does require an additional board to reach the max brightness.
4) Hassle / Reliability – well this DIY project requires some hassle by definition, doesn’t it?
Other things you’ve mentioned:
- Since you do bother about the max brightness, I would suggest to bother about 10 bit as well (or don’t bother about both – your screen will get quite bright (really bright!) without an additional board). So and it you wish to go with 10 bit, then R1811 is your choice.
- Can’t say about controlling with the keys but there is a 3rd party app (listed somewhere in this thread) that allows to change brightness without going to the menu
- It is possible to reuse the built-in speakers but it requires some hassle that you wish to avoid. Basically you have four pins on each speaker (A1, B1, C1, D1 and A2, B2, C2, D2) and four pins on the board (W, X, Y, Z). And you have to manually make Y-shaped wires that will connect A1+A2 to W, B1+B2 to X and so on. The seller of R1811 offers custom speakers that already have Y-shaped wires, so all you‘ll need is to connect them to the board. But then you’ll have to remove the original speakers…
Overall it’s up to you what level of hassle/perfection you wish to have. There are lots of things you can skip: making the original power button working, making the power go via original cord, support additional cables/ports, put the board and power brick inside or outside of the case…
Good luck and hope you’ll succeed!
Oh and one thing to mention that was quite a bummer for me. If you calibrate your display and adjust RGB values – once you turn board’s power off – all those settings get reset. That’s annoying and AFAIK there is no hardware fix for that yet.
1) I don't know of any such PCB. I suppose if you are working with a 5K iMac that has USB-C ports, you could theoretically mount a connector behind the hole in the aluminum. In my opinion, it is far easier (but admittedly less elegant) to just pop out the RAM door, and run whatever wiring you need out through the big hole in the iMac chassis. A PCB large enough to span all of the ports would likely be prohibitively expensive to make any sense. I guess a smaller PCB and a 3D-printed bracket could be used, but that is a ton of work when there is already a huge hole in the back of the iMac. Perhaps some panel-mount connectors mounted on a 3D-printed RAM door replacement would make more sense.
) --if you run the webcam USB wire through the RAM hatch, the webcam's USB cable can plug directly into the USB port on the R1811 board, so the webcam will show up over the primary R1811 USB-C. If you are up for a soldering challenge, it should theoretically be possible to reuse an existing iSight camera from another Apple product or to use a PC laptop webcam module. Many, but not all, webcam modules use USB as their communication protocol, so it would be a matter of determining their pinout and soldering the right wires to a USB cable.Hello David. I bought this USB web cam and it is not showing up in OSX. I currently have it plugged into the R1811 board and the R1811 board is connected via single DP 1.4 cable. Is this sufficient or should I plug in the USB-C as well or extend the USB plug to plug it directly in the my Mac? Thanks for the help1) I don't know of any such PCB. I suppose if you are working with a 5K iMac that has USB-C ports, you could theoretically mount a connector behind the hole in the aluminum. In my opinion, it is far easier (but admittedly less elegant) to just pop out the RAM door, and run whatever wiring you need out through the big hole in the iMac chassis. A PCB large enough to span all of the ports would likely be prohibitively expensive to make any sense. I guess a smaller PCB and a 3D-printed bracket could be used, but that is a ton of work when there is already a huge hole in the back of the iMac. Perhaps some panel-mount connectors mounted on a 3D-printed RAM door replacement would make more sense.
2) The R1811 driver board already has an onboard speaker amplifier. If you see some of the above posts from this week, there is some discussion of using this amplifier to power the iMac speakers. Connecting the speakers would be a matter of cutting and soldering the right wires from the original speakers. (Personally, I went with better-sounding external bookshelf speakers instead, which is how I previously used the iMac before converting it into a monitor. I do see the benefit in having an all-in-one solution with speakers built-in if limited desk space is a concern.)
3)I know of some smaller USB cameras that fit, but the image quality isn't fantastic. The easiest way to get the best video quality would be to use an external webcam sitting atop the iMac (this looks a little less neat, but it wouldn't take up extra desk space
4) I believe the driver board itself supports HDR, but most of the available iMac panels themselves do not. The 2020 iMac LCD panel might work with HDR, but I haven't heard of anyone who had success with this before. To achieve enough brightness for the HDR spec, you would almost definitely need to use the constant current LED driver board in addition to the R1811 board.
5) I would make sure you find a power supply that is really well suited to the task of running all these electronics. I have not been completely satisfied with the one my R1811 came with, as it gets really hot and sometimes seems to struggle. I've been meaning to replace it with something of higher quality, with a greater amperage output.
Displayport doesn't pass through USB signals, only video signals. The USB-C connector should send power, video, and USB all at once. If your computer supports USB-C, you can use it instead of displayport. If your computer doesn't support USB-C, you'll need to directly plug the webcam into a USB-A port on your computer (a USB 2/3 extension cable is probably fine).
