DIY 5k Monitor - success :-)

[yurazazik]

Hello everyone! I’m still not giving up. I even started to think I might have broken my LED panel while disassembling my iMac. So today, I decided to test the LM270QQ1 panel again by reconnecting it to the iMac… And everything works!!! However, the 1811 board still doesn’t display any image.

I’m leaning towards the issue being with the backlight wires or the eDP cable, and for now, nothing else comes to mind.

 

[Regulus67]

However, the 1811 board still doesn’t display any image.

I’m leaning towards the issue being with the backlight wires or the eDP cable, and for now, nothing else comes to mind.

Does the power brick light turn red when you use the R1811? Or does it stay blue?
I had a red light when my eDP cable was broken. So the power brick is probably able to sense if the power-draw is within normal operation.
The green light diode is on the control board

edited because I had wrong colours on the power brick

 

[yurazazik]

Does the power brick light turn green when you use the R1811? Or does it stay red?
I had a red light when my eDP cable was broken. So the power brick is probably able to sense if the power-draw is within normal operation

yes power is green

 

[Regulus67]

yes power is green

If you got a new eDP cable, then it has to be the backlight cable or backlight connectors that has been damaged, bent pins?

Could be that it is not faulty at all.
Perhaps the problem is the computer you are trying to connect it to? If possible, try to test the display with another computer.
I could not find what you want to connect the display to

 

[yurazazik]

If you got a new eDP cable, then it has to be the backlight cable or backlight connectors that has been damaged, bent pins?

Could be that it is not faulty at all.
Perhaps the problem is the computer you are trying to connect it to? If possible, try to test the display with another computer.
I could not find what you want to connect the display to

I connected to the mac studio max with m2 processor and used ucb-c to DP CABLE

 

[PaulD-UK]

The R1811’s LED won’t show a green light if the input isn’t fully working.

The backlight cable is most likely the problem but the board’s backlight circuitry output also needs checking.

With care as it should be about 30-40 volts.

 

[Regulus67]

The R1811’s LED won’t show a green light if the input isn’t fully working.

I just tested mine. And yes, the light is blue on the power brick. It was only red when the eDP cable was drawing to high voltage then, I suppose. As it had an electrical short and melted.

The control board diode is red, until the mac is sending video to the R1811 card. Then it turns green. As you say

 

[lehnek]

I’ve been reading up on this thread for a few months now, and I’ve purchased most of the materials I plan to use for the project and gotten to the point of testing a lot of the basic functionality successfully. I’ve also started modeling some 3D parts and printing them to align connectors to ports and mount my R1811 board. (Happy to share once I’m happy with them.)

From reading past posts, I see that there doesn’t seem to be an available connector for the speaker or stock imac fan to go to. I hesitate to cut off the existing connector to splice in wires because it will be easy to lose track. What have people found is the best way to get solid connections to each of these systems? If people are somehow just pushing wire ends into the connectors, I would love some detail on what type of wire worked for you, since doing so seemed less than ideal. Thank you so much in advance. I’ve been really enjoying the ingenuity and cooperation through this thread!

 

[DaveF]

Anyone know if a Mac mini m4 can drive 5K by HDMI with the R1811? I see the R1811 supports it. But from Apple's tech specs, it no more than 4K is supported on HDMI for the m4 (not Pro). But if anyone knows otherwise, I realize I'd rather use HDMI and free up a USB-C port to connect a hub to.

 

[PaulD-UK]

@DaveF
According to Apple's Tech Specs:
HDMI display video output

• Support for one display with up to 8K resolution at 60Hz or 4K resolution at 240Hz (M4 and M4 Pro)

So if you are not using two other displays from the TB4 ports, the M4 performs exactly the same as the M4 Pro.
Which means you should get the 5K/60 10 bit you want if you are using the HDMI 2.1 version of the R1811.
And you are using an 'Ultra Certified HDMI Ultra High Speed' 8K cable.

However...
MacOS has a quirk that means it often assumes it is a TV you are connecting over HDMI, and for TVs , YCbCr 4.2.2 is an acceptable colour mode.
So that is what you may get as the default even if it is a computer monitor that is connected, and you will need Better Display or SwitchResX to switch to RGB.

 

[DaveF]

@DaveF
According to Apple's Tech Specs:
HDMI display video output

• Support for one display with up to 8K resolution at 60Hz or 4K resolution at 240Hz (M4 and M4 Pro)

So if you are not using two other displays from the TB4 ports, the M4 performs exactly the same as the M4 Pro.
Which means you should get the 5K/60 10 bit you want if you are using the HDMI 2.1 version of the R1811.
And you are using an 'Ultra Certified HDMI Ultra High Speed' 8K cable.

However...
MacOS has a quirk that means it often assumes it is a TV you are connecting over HDMI, and for TVs , YCbCr 4.2.2 is an acceptable colour mode.
So that is what you may get as the default even if it is a computer monitor that is connected, and you will need Better Display or SwitchResX to switch to RGB.

I read that as 4K @ 240Hz is supported by m4 but 8K @ 60Hz is m4 Pro only. (Otherwise that entire bullet would have been under the m4 capabilities. Or broken out as for both and not listed under m4 Pro with an ambiguous parenthetical. Apple’s tech specs aren’t well written.) I was hoping someone who has tried can confirm the meaning one way or the other.

 

[PaulD-UK]

"Otherwise that entire bullet would have been under the m4 capabilities"
I agree there could be ambiguity, but Apple are very precise, and they listed:

• Three display arrangements...
• Two display arrangements...

For each of M4 and M4 Pro, because each is different, and one USB-C display max is the same as with two.
Then, jointly for HDMI, because it doesn't need to be written twice:

• Support for one display with up to 8K resolution at 60Hz or 4K resolution at 240Hz (M4 and M4 Pro)

So I take that bullet point precision to mean exactly what it says.

Hopefully someone will confirm it in practice.

 

[DaveF]

"Otherwise that entire bullet would have been under the m4 capabilities"
I agree there could be ambiguity, but Apple are very precise, and they listed:

• Three display arrangements...
• Two display arrangements...

For each of M4 and M4 Pro, because each is different, and one USB-C display max is the same as with two.
Then, jointly for HDMI, because it doesn't need to be written twice:

• Support for one display with up to 8K resolution at 60Hz or 4K resolution at 240Hz (M4 and M4 Pro)

So I take that bullet point precision to mean exactly what it says.

Hopefully someone will confirm it in practice.

I understand how you’re reading it. It might well mean that. Hopefully you’re right and I’m wrong on this.

If nothing else, I’ll buy the $15 HDMI cable and test it out when I have time after Christmas. 🎅 🎄

 

[Donald.l.Smith]

I'm ready to give up on my IMac 5k conversion.

History: Winter of 2020 during covid when installing macos update imac became bricked.
No combination of key hold-downs when powering up would cause it to go into a boot sequence.
The screen would light up and the boot noise would occur but that was all, nothing on the screen.
Even thought the install screwed up the T2 firmware and tried using Apple Conigurator to resolve, no luck.
Put it aside and essentially forgot about it as I mostly used my macbook anyway.


Present: Came across videos on youtube about converting to 5k monitor.
Apple came out witn M4 mac mini.
Had idea of trying to convert the imac as a monitor for the mac mini.
Bought a board (StoneTaskin JRY-W9CUHD-AA1) for my screen type (LM270QQ1) and a 24 volt 5 amp power supply (Alitove).
Stripped the imac and connected the monitor via (HDMI) to a working Raspbery PI.
No go, screen lights up as before, still nothing on the screen.
Backlight connecion appears correct and (logic board) connection only plugs in one way.
Control board led lights up when button pressed to apply power.

Find it hard to believe that installing macos update would kill the screen.
More likely the (T2) on the (logic) board.
What does a failed monitor screen look like?

Eventually bought a M4 mac mini and a Dell S2721QS 4k monitor during Amazons black friday sales
and am satisfied with the results, probably don't need 5k, but I don't like to admit defeat
so I will continue to try to get the imac display to work for a few more weeks before giving
up and selling what I can on ebay.

Anybody have any suggestions on what I can try? Or is it hopeless?

 

[PaulD-UK]

@Donald.l.Smith
It seems that a Raspberry Pi can't do 5K.
'Doesn't work' is the google search wording...

...so maybe the JRY--AA1 is set to its HDMI 5K/30Hz mode and not dropping to a resolution the Pi can work at?
Anyway that doesn't really matter as you have a M4 Mac mini.

So the testing you are talking about is with the Mac mini?
With a HDMI cable?
And that doesn't work?
Are you sure it is a HDMI 2.0 cable capable of 4K, or a certified Ultra High Speed 8K HDMI cable?

And, have you checked that the AA1 is set to the correct HDMI input?
It should be possible to cycle through all the inputs by pressing one of the buttons on the Control Strip, possibly not the Menu button but the Exit button?

What does 'screen lights up' look like?
A black screen lit up by the backlight so it is slightly grey?

It is better to connect the Mac mini using a Thunderbolt 3 cable, or a USB-C cable that you know works with a video to a monitor - not a SSD cable.
It would be better still to use a USB-C to DisplayPort 1.4 8K adapter cable , with the USB-C plugged into the Mac and the DisplayPort into the JRY--AA1.

That way the iMac screen should receive a proper 5K/60 signal.

Also if you connect the AA1 to the Mac mini and also connect the Dell, then you can check on the Dell if the Mac sees anything when you power up the AA1.
You will see if it sees the AA1 and iMac display in System Settings > Displays.

Finally, Does the eDP cable from the top front socket on the AA1 board to the 60 pin screen connector look OK, and plugged in properly?
Other makes of board will not show a working LED light on the Control Strip if there is a problem, but will stay with the red stand-by LED lit.
I don't know how the AA1's LED changes to show everything is operating properly.

 

[soisaac]

I got the U49 board from Ali Express and connected it to my 2014 5K iMac panel, but I'm only seeing the right half of the display image (and stretched as shown in the attached image when I had it connected to a Windows PC for troubleshooting purposes). Is it possible I connected something wrong or that the board is bad, or could this be some configuration issue? Any help would be appreciated! I can't even navigate the on-screen display to troubleshoot with it like that. It's the same behavior with HDMI, DP, and Thunderbolt cables. I'll admit that my HDMI and DP cables may not be very recent, but if that were the limiting factor, wouldn't it just limit the resolution rather than showing me half of the image?

 

[PaulD-UK]

@soisaac Only a couple of U49 users have reported here, and neither of them are active contributors of this thread.
They both has good results using MacOS to drive the board, although one reported problems with lo-res streamed video scaling...
Also not as much experience with Windows.

Do you mean you tried it with MacOS, and it only showed the right half of the image, and restricted it to the right side of the screen panel?
MacOS has a mode like that for computers that have GPUs that don't support DSC (compression).
This dual SST mode was used with the LG Ultrafine 5K Thunderbolt displays, and also the Dell UP2715K 5K TB monitor sold in 2015.
It's enabled by the EDID signal the monitor controller board sends to the Mac, and is only visible using a utility like Better Display or SwitchResX.

The R9A18 has this mode, and you have to have two cables from the Mac to the board (as does the Dell monitor).
It has different firmware, and this dual-cable mode is an option in the OSD, that the firmware enables.

So if your U49 has a similar 'dual input' mode then it would need two cables to work properly.
And the dual setting would need to be deselected in to OSD to get single-input operation to work.
All that is speculation, as I haven't heard of this mode of operation for the U49...

Only MacOS has this mode, so maybe that's why Windows shows a stretched image?
I've no expertise in the details...
Hopefully someone will be able to respond.

Edited to add further info.

 

[jimbos561]

Hi, I have a question about the R1811 controller board. The fan on the controller board turns on, but the five-button key light is not functioning. I used to see a green or red indicator light, but now there are no lights at all, only the fan is working. I accidentally touched the metal part of the power supply with the controller board, and since then, it has not been working properly. Do you think my controller board is dead?

 

[6-Colors]

Does someone know how to connect a 5D rocker instead of the original controller of the jry-w9cuhd-aa1 board? I connected 8 cables via 2x 4 pin jst connectors to the board but can´t figure out how to connect it. And I don´t need the power button connected as I´m using the imac power button as so. The Layout doesn´t make sense to me, as the menu isn´t routed to anything but the menu button on the original controller works. Thanks in advance

I’m looking for advice on how to mount the same 5d rocker switch through the ethernet port. Unfortunately I don’t have access to a 3d printer.

@sadontsev wrote they used super glue. I’m curious how you mounted yours, @wafer2000

Any other’s advice is welcome!

 

[PaulD-UK]

@jimbos561 "I used to see a green or red indicator light, but now there are no lights at all, only the fan is working. I accidentally touched the metal part of the power supply with the controller board, and since then, it has not been working properly. Do you think my controller board is dead?"

Yes, accidentally short-circuiting (for even a few milliseconds) any electronic device will burn out its micro-components.
Not all the board will be affected, just that part of the circuit that was between the 24v power source (or higher (~60v) in the backlight circuit) and the point of the short.

A board repair specialist should be able to find the point of failure, and repair it if spare components are available.
But it needs an expert...

However you could examine the PCB closely to see where the board touched the PSU case, and if any components or circuit traces show any signs of damage.

 

[Xarl-li]

@antibolo "I had hoped that eventually someone would come out with a "everything you need DIY kit" that neatly replaces the iMac internals and reuses the ports on the back, but it appears that's not the case."

I think that will remain so for the immediate future...
But there is a Kickstarter micro-company that reportedly say's it's on their 'to do list'.

Anyway part of the advantage of a DIY conversion is that you gain the flexibility of using DP and HDMI ports instead of just the iMac's original USB-C only limitation.

But I can't guess what the manufacturing cost would be of reproducing Apple's internal port layout for a small scale run...

View attachment 2461633

Its a great idea!

 

[Xarl-li]

Yes, I suspected it will not work but it was worth trying.

A "12Vdc to 24Vdc step up converter" is a good suggestion. Thank you. I might try that.

I like the Mean Well LRS-200-24 8.8A, a larger foot print but a good option.

I have the laptop power brick which works well, however, Xarl-li's setup, post #1952, shows a less expensive option. He is using the AA1 board and opted for the 6A version, I opted for the 9A version.

This approach requires tapping/connecting into the iMac's power connector for a better look and fit inside the unit. You will need a female 3 pin Micro-Fit 3.0mm connector.

Again thank you for all your suggestions.




View attachment 2462569


View attachment 2462558
Female 3 pin Micro-Fit 3.0mm connector

View attachment 2462596

In my project I used the FKSI of 24v and 6A, it is more than enough, it does not heat up because it is too much, and on thingiverse I have the STL shared in case you are interested. There is also the STL for the stepdown regulator + thermostat so that the original fan can be used, etc.

 

[Donald.l.Smith]

@Donald.l.Smith
It seems that a Raspberry Pi can't do 5K.
'Doesn't work' is the google search wording...

...so maybe the JRY--AA1 is set to its HDMI 5K/30Hz mode and not dropping to a resolution the Pi can work at?
Anyway that doesn't really matter as you have a M4 Mac mini.

So the testing you are talking about is with the Mac mini?
With a HDMI cable?
And that doesn't work?
Are you sure it is a HDMI 2.0 cable capable of 4K, or a certified Ultra High Speed 8K HDMI cable?

And, have you checked that the AA1 is set to the correct HDMI input?
It should be possible to cycle through all the inputs by pressing one of the buttons on the Control Strip, possibly not the Menu button but the Exit button?

What does 'screen lights up' look like?
A black screen lit up by the backlight so it is slightly grey?

It is better to connect the Mac mini using a Thunderbolt 3 cable, or a USB-C cable that you know works with a video to a monitor - not a SSD cable.
It would be better still to use a USB-C to DisplayPort 1.4 8K adapter cable , with the USB-C plugged into the Mac and the DisplayPort into the JRY--AA1.

That way the iMac screen should receive a proper 5K/60 signal.

Also if you connect the AA1 to the Mac mini and also connect the Dell, then you can check on the Dell if the Mac sees anything when you power up the AA1.
You will see if it sees the AA1 and iMac display in System Settings > Displays.

Finally, Does the eDP cable from the top front socket on the AA1 board to the 60 pin screen connector look OK, and plugged in properly?
Other makes of board will not show a working LED light on the Control Strip if there is a problem, but will stay with the red stand-by LED lit.
I don't know how the AA1's LED changes to show everything is operating properly.

Testing was on the Raspberry Pi with HDMI cable , don't know the type.
Screen lights up as slightly grey.
I just tried it on my M4 Mac mini, with the Dell monitor hooked up via HDMI and the IMAC panel hooked up via 8K display port cable.
It recognized the IMAC panel, the Control Strip led light is green, but the display is still grey.
When I select and deselect High Dynamic Range the screen flashes black and then grey again, no display.
Selecting different resolutions, brightness or color profile has no affect.
Here is a screen capture of System->Displays.
60 pin connector appears ok. I will try reconnecting it to see if it changes .

Thanks for your help.

 

[PaulD-UK]

@Donald.l.Smith turn off HDR in System Settings. These boards and iMac panels don’t have the brightness range to do HDR, and give a washedout image grey picture.

It does sound like a eDP cable problem, or with the connection to the board. Or the board.

Edit: But the board light being green is a good sign that everything is OK with the board.

 

[Donald.l.Smith]

@Donald.l.Smith turn off HDR in System Settings. These boards and iMac panels don’t have the brightness range to do HDR, and give a washedout image grey picture.

It does sound like a eDP cable problem, or with the connection to the board. Or the board.

Edit: But the board light being green is a good sign that everything is OK with the board.

I removed and reconnected the 60-pin connector (only goes in one way) and still only have a grey screen.
HDR is turned off.
If the DP cable is not plugged into the AA1 board the led is red, when I plug in the DP cable the led turns green.
If the backlight cable was not connected correctly would the screen be black and not light up grey?
I assume the mac gets its resolution information etc from the board and not the screen.
When I get a chance I'll look closer at the 60-pin cable connection at the AA1 board end.
It came already attached.
I'll email StoneTaskin to see what they think.