DIY 5k Monitor - success :-)

[PaulD-UK]

@TheCluelessOne
The ground E pin, NOT the Neutral.
Leave the Ground input line that connects to the mains input plug into the iMac case connected to the original stand-off fixing.
Connect your PSU so any metal case and the E ground input connection are connect to the iMac aluminium case - with a good electrical connection.

Make sure the incoming Live and Neutral mains connections are well insulated, from the Molex input connector to the L and N pins on the PSU.

 

[TheCluelessOne]

@TheCluelessOne
The ground E pin, NOT the Neutral.
Leave the Ground input line that connects to the mains input plug into the iMac case connected to the original stand-off fixing.
Connect your PSU so any metal case and the E ground input connection are connect to the iMac aluminium case - with a good electrical connection.

Make sure the incoming Live and Neutral mains connections are well insulated, from the Molex input connector to the L and N pins on the PSU.

Apologies for my ignorance here, when you say insulated wont the standard cable sheilding be enough? I'll be using a similar wago clip to connect the molex stripped cable (joined with some cable) to reach the PSU. Is there anything I need to consider?

I bought the LRS-200-24 PSU and its arrived today, it looks pretty chunky; I havent had time to open to open up my enclosure but has anyone been successful at installing it into the case? I'm not sure it will fit.

 

[TheCluelessOne]

• When my connected machine is sleeping, the screen will also go into a sleep state (backlight off), but then a minute later turn back on (backlight is on, and status LED goes Green from Red) and then it just cycles through this every minute. I have to press the power button to turn it off completely to stop it.

Just wanted to also see if anyone else has experienced this? Is there a fault in the cable or something?

 

[PaulD-UK]

@TheCluelessOne "...when you say insulated wont the standard cable shielding be enough?"

Possibly. There is no such thing as 'standard' cable.
Every cable sold has a safe maximum voltage and current rating.

Most likely your cable will be 'low voltage' - which may be OK for mains voltage, but isn't rated for that use.
The easiest way to get a short length of 'mains rated' cable is to use the cable from a mains-power appliance, and strip the outer protective insulation off it, leaving the coloured insulation that identifies the wires in place.

 

[specmedia]

Hey folks,

I’m looking for some advice on the best controller board and adapter setup for my project.
I have a Mac Pro (Late 2013, D700, Thunderbolt 2), and I want to turn a 27" iMac 2015 (LM270QQ1) into a standalone monitor.

Which board would you recommend for the best possible image quality and compatibility with this Mac?
And which Thunderbolt 2 → DisplayPort adapters or cables work well in this setup?

Any proven combinations or tips would be really appreciated.


Thanks!

 

[braunico]

Apologies for my ignorance here, when you say insulated wont the standard cable sheilding be enough? I'll be using a similar wago clip to connect the molex stripped cable (joined with some cable) to reach the PSU. Is there anything I need to consider?

I bought the LRS-200-24 PSU and its arrived today, it looks pretty chunky; I havent had time to open to open up my enclosure but has anyone been successful at installing it into the case? I'm not sure it will fit.

Yes many of us have. Here is mine https://forums.macrumors.com/threads/diy-5k-monitor-success.2253100/post-34249782
take care not to put it too high/low or it'll block when puting back the lcd.

Regarding your other questions

• On my picture you see the green GROUND cable going out of the PSU and wired to the chase, at the same place where the imac power plug Ground is also wired to the case
• I do not have the same problem you do, when it sleeps it sleeps. I'm using USB-C.
• For the cables, i'm no pro and maybe @PaulD-UK can confirm
  • Those are rated 600V
  • INPUT : 200W at (for France 220V) this makes max current pretty low => sqrt (200/220) ~1 A. I used 18AWG cable to have some margin
  • OUTPUT 200W at 24V => max 2,9 A. I used as prewired cable (cf my build) but in theory any 24AWG or lower in my link should do. If it fits, length of cable are quite short so go big

PS : I used a prewire cable because it could not find a DC connector that was rated for those currents

 

[PaulD-UK]

@specmedia
The only board that will give 5K from a 2013 Mac Pro is a R9A18, connected from your Mac with two separate miniDP to DP 1.2 cables into the two DP inputs on the board.
You don’t need TB cables, as only miniDP to DP 1.2 is needed.

If you want to use the monitor with a modern Mac (using a single cable) in the future then a R1811 board can have special firmware to allow connection with two DP 1.2 cables, but you can only flash the replacement firmware on a Windows PC with a DP output.

Every other board only works with 2019 or later Macs.
The R9A18 can be used with later Macs, using a TB 3 to Dual DP 1.2 adapter, with the adapter connected to the two DP cables to the board.

 

[TheCluelessOne]

@TheCluelessOne "...when you say insulated wont the standard cable shielding be enough?"

Possibly. There is no such thing as 'standard' cable.
Every cable sold has a safe maximum voltage and current rating.

Most likely your cable will be 'low voltage' - which may be OK for mains voltage, but isn't rated for that use.
The easiest way to get a short length of 'mains rated' cable is to use the cable from a mains-power appliance, and strip the outer protective insulation off it, leaving the coloured insulation that identifies the wires in place.

So I bought two bits of cable from AliExpress thinking it would be good enough to connect between the inlet and the PSU, I take it they wont be suitable?
3 Core Solid Copper Cable - 16AWG
2 Pin Cable - 18AWG
(Not even sure why I bought two, I ordered them pretty late lol)

 

[TheCluelessOne]

Yes many of us have. Here is mine https://forums.macrumors.com/threads/diy-5k-monitor-success.2253100/post-34249782
take care not to put it too high/low or it'll block when puting back the lcd.

Regarding your other questions

• On my picture you see the green GROUND cable going out of the PSU and wired to the chase, at the same place where the imac power plug Ground is also wired to the case
• I do not have the same problem you do, when it sleeps it sleeps. I'm using USB-C.
• For the cables, i'm no pro and maybe @PaulD-UK can confirm
  • Those are rated 600V
  • INPUT : 200W at (for France 220V) this makes max current pretty low => sqrt (200/220) ~1 A. I used 18AWG cable to have some margin
  • OUTPUT 200W at 24V => max 2,9 A. I used as prewired cable (cf my build) but in theory any 24AWG or lower in my link should do. If it fits, length of cable are quite short so go big

PS : I used a prewire cable because it could not find a DC connector that was rated for those currents

Interesting, I tried a test fit but it looked like the case was too shallow to have it in place under the screen, I'll have to try it again. How is yours mounted btw? I see you've got some cable ties onto the anchor points but does this not mean the front leans against lcd panel?

I have another USB C cable coming, I will test to see if its (hopefully) just a dodgy cable.

Your comment about the output, the mean well PSU has a screw to adjust the voltage. I take it you adjust this with a multimeter attached and set it to 24V? I ordered this 18AWG pigtail from AliExpress to connect PSU -> board, is the AWG rating too low?

 

[PaulD-UK]

@TheCluelessOne
"So I bought two bits of cable from AliExpress thinking it would be good enough to connect between the inlet and the PSU, I take it they wont be suitable?"

The AliEx page says:
Voltage 81-600V
Which is fine, that is suitable cable.

AWG18 is fine for the barrel plug into the board, it's rated at 10A.

 

[TheCluelessOne]

@TheCluelessOne
"So I bought two bits of cable from AliExpress thinking it would be good enough to connect between the inlet and the PSU, I take it they wont be suitable?"

The AliEx page says:
Voltage 81-600V
Which is fine, that is suitable cable.

AWG18 is fine for the barrel plug into the board, it's rated at 10A.

Legend! Thank you very much for taking a look.

I was looking at some printed parts, has anyone had any success with this or this for the SA1 board? I had this printed for me and it turns out it doesn't fit for the SA1 board, the screw points to match up at all.

 

[bulabula2001]

Legend! Thank you very much for taking a look.

I was looking at some printed parts, has anyone had any success with this or this for the SA1 board? I had this printed for me and it turns out it doesn't fit for the SA1 board, the screw points to match up at all.

I used the one in the second link, however trimmed down the holder to use less plastic.
You can find it here.
I use it in a 2017 iMac.

 

[PaulD-UK]

@TheCluelessOne
Unfortunately the 3D print designs for DIY boards are not very well documented. 😕

The SA1 mount design uploaded by @gul1ver seems to be designed to fit a 2012-early2014 2K iMac case, which has the stand-offs in a different place.

The SA1 3D design uploaded by @Xarl-li was a modification of the design made for a JRY--AA1 board in a different (2015) iMac case.
It originally didn't fit.
He redesigned it, so it may now work in the 2017 iMac case, with some modifications still necessary...

The 3D design from @pnwkayaker is for a later iMac case, so should fit in a 2019 conversion.

But the thing that I'm not sure about is that both @Xarl-li and @pnwkayaker have mounted the SA1 board close to a printed backing plate, which will restrict airflow to the back of the board...

Also, @pnwkayaker has fitted his board towards the top of the case, which means that it is only cooled through the case - a fan can't be used to cool that part of the case.

So if USB-C PD charging is used, the backing board and the high position may result in a build-up of heat?
The SA1 board can supply up to 90W of PD charging power, and that will make the SA1 run hotter.
Even without PD charging it is quite a hot-running board.

 

[Slopes]

I'm going ahead with this PSU I bought from AliExpress. I've hooked up all the components to this (SA1, panel, etc) and everything is working with my Macbook Air. This may be an obvious question but how to I ground this PSU? The board has Live and Neutral terminals but i can see no connector for the earth wire. Do I only need to connect the earth wire to one of the metal standoffs on the iMac's case?

 

[Slopes]

@TheCluelessOne
Unfortunately the 3D print designs for DIY boards are not very well documented. 😕

The SA1 mount design uploaded by @gul1ver seems to be designed to fit a 2012-early2014 2K iMac case, which has the stand-offs in a different place.

The SA1 3D design uploaded by @Xarl-li was a modification of the design made for a JRY--AA1 board in a different (2015) iMac case.
It originally didn't fit.
He redesigned it, so it may now work in the 2017 iMac case, with some modifications still necessary...

The 3D design from @pnwkayaker is for a later iMac case, so should fit in a 2019 conversion.

But the thing that I'm not sure about is that both @Xarl-li and @pnwkayaker have mounted the SA1 board close to a printed backing plate, which will restrict airflow to the back of the board...

Also, @pnwkayaker has fitted his board towards the top of the case, which means that it is only cooled through the case - a fan can't be used to cool that part of the case.

So if USB-C PD charging is used, the backing board and the high position may result in a build-up of heat?
The SA1 board can supply up to 90W of PD charging power, and that will make the SA1 run hotter.
Even without PD charging it is quite a hot-running board.

As a 3D printing enthusiast, I would be careful about relying too much on this for mounting internal components. PLA (the most common and easiest to use filament) has a very low melting temperature and any item printed with it will begin to soften and deform at around 55C

 

[PaulD-UK]

@Slopes "...how to I ground this PSU? The board has Live and Neutral terminals but i can see no connector for the earth wire. Do I only need to connect the earth wire to one of the metal standoffs on the iMac's case?"

The original mains power Earth/Ground wire is connected to a standoff at the bottom of the case.
So mount the PSU to one of the iMac case standoffs with a metal screw.
Then carefully power it up and check that there is no problem with electrical leakage to the case...

The mount holes are marked G so there shouldn't be a problem... 😉

 

[braunico]

Interesting, I tried a test fit but it looked like the case was too shallow to have it in place under the screen, I'll have to try it again. How is yours mounted btw? I see you've got some cable ties onto the anchor points but does this not mean the front leans against lcd panel?

I have another USB C cable coming, I will test to see if its (hopefully) just a dodgy cable.

Your comment about the output, the mean well PSU has a screw to adjust the voltage. I take it you adjust this with a multimeter attached and set it to 24V? I ordered this 18AWG pigtail from AliExpress to connect PSU -> board, is the AWG rating too low?

I'm using a 2017 iMac, maybe the case is deeper.
As stated in post it has to be "around the vertical middle" of the case since the case does not have the same depth everywhere. Its heights should roughly be the same as the left speaker.

Yes the plastics ties are the only mounting i used, they "kinda" maintain the PSU in both directions.
I also used subdriver trick to reuse the case mounts I had snapped off. My picture was taken before adding them. I'll post a new one when reopening.
I think the plastic strip also prevent the PSU from leaning agains the LCD but this is not perfect, would love to hear any better solution.
If you have whats needed, you could add some screw with colar on the case mount to the top right of the psu.

That said the screen is usually tilted back so this has not been a problem so far.

---

The PSU output should be 24V when out of factory but yeah you can use the little screw if needed. I do not recall if I did even test this output. (with a multimeter)

 

[TheCluelessOne]

@TheCluelessOne
Unfortunately the 3D print designs for DIY boards are not very well documented. 😕

The SA1 mount design uploaded by @gul1ver seems to be designed to fit a 2012-early2014 2K iMac case, which has the stand-offs in a different place.

The SA1 3D design uploaded by @Xarl-li was a modification of the design made for a JRY--AA1 board in a different (2015) iMac case.
It originally didn't fit.
He redesigned it, so it may now work in the 2017 iMac case, with some modifications still necessary...

The 3D design from @pnwkayaker is for a later iMac case, so should fit in a 2019 conversion.

But the thing that I'm not sure about is that both @Xarl-li and @pnwkayaker have mounted the SA1 board close to a printed backing plate, which will restrict airflow to the back of the board...

Also, @pnwkayaker has fitted his board towards the top of the case, which means that it is only cooled through the case - a fan can't be used to cool that part of the case.

So if USB-C PD charging is used, the backing board and the high position may result in a build-up of heat?
The SA1 board can supply up to 90W of PD charging power, and that will make the SA1 run hotter.
Even without PD charging it is quite a hot-running board.

Thank you for this detailed write up.

I’m beginning to think is it worth it trying to fit everything inside and have to securely mounted. There’s some variations in the screw points in the cases I weren’t aware of, I have the late 2015 model so I’m not sure any of the mounts above will actually work in that case.

Right now I have just hang the board on two zip ties (through the screw holes) and used black insulation tape to tape through the loop on to the back of the panel. I’ve put some insulation tape behind the panel so the bottom of the board doesn’t touch the metal.

I was really hoping I could go without using a fan as I wanted the screen to be silent so the fan airflow wasn’t even something that crossed my mind. The only thing inside the case is the board atm, and I’m hang an external PSU (which I was planning change to the internal caged one instead). I’m guessing this won’t work in the long run and a fan does need to be installed?
I am als doing PD at 90W to my laptop

 

[PaulD-UK]

@TheCluelessOne
@Aiwi has used an internally mounted LRS-200-24 in his build (link to his build blog).
The PSU shouldn't be mounted any higher than the speakers.

You can fix altered standoffs in new places as required, using epoxy glue.
Sandpaper the aluminium on both standoff and case to help it stick:

If you are using an SA1 board without a fan it needs to be mounted lower in the case so heat can escape better.

 

[Slopes]

@Slopes "...how to I ground this PSU? The board has Live and Neutral terminals but i can see no connector for the earth wire. Do I only need to connect the earth wire to one of the metal standoffs on the iMac's case?"

The original mains power Earth/Ground wire is connected to a standoff at the bottom of the case.
So mount the PSU to one of the iMac case standoffs with a metal screw.
Then carefully power it up and check that there is no problem with electrical leakage to the case...

The mount holes are marked G so there shouldn't be a problem... 😉

Thanks Paul - I missed those tiny 'G' markings!

 

[TheCluelessOne]

Yes the plastics ties are the only mounting i used, they "kinda" maintain the PSU in both directions.
I also used subdriver trick to reuse the case mounts I had snapped off. My picture was taken before adding them. I'll post a new one when reopening.
I think the plastic strip also prevent the PSU from leaning agains the LCD but this is not perfect, would love to hear any better solution.
If you have whats needed, you could add some screw with colar on the case mount to the top right of the psu.

Thanks for sharing, this might work.. it looks like I’ll have to put in the left speaker in again so the PSU has no give in between. How were those screw mounts put back on at the bottom? With just glue?

I think if there’s no left and right movement, the single zip tip at the top threaded through the case might hold it up. Then there’s just the issue of it falling forward onto the panel. I’ll need to add something on top so they don’t meet.

 

[TheCluelessOne]

Nevermind just seen Paul’s post about the fixings after I posted!

 

[TheCluelessOne]

I came across these 3d printed mounts that hold the board closer to the ram door so should hopefully be better for ventilation. Anyone used it before? And would it be suitable for the SA1 board?

 

[PaulD-UK]

@TheCluelessOne
I think those mounts were designed for the AA1 board.
The Control Strip cover is the same as the SA1, so that would be OK.

 

[TheCluelessOne]

@TheCluelessOne
I think those mounts were designed for the AA1 board.
The Control Strip cover is the same as the SA1, so that would be OK.

It was the board mounts I was interested in 🥲