DIY 5k Monitor - success :-)

[redheeler]

Is the R1811 specific to the exact revision of the panel? I don’t have the tools to open the iMac and look with me at the moment.

(Hollowing out my trusty iMac feels wrong but unfortunately it’s gotten to the point that I need newer hardware on my desk. At least the display can continue to serve me well).

 

[Regulus67]

As far as I understand. There are 6 versions, based on the panel and size.
I have the LM270QQ1 version for my iMac 27" late 2015 model

 

[PaulD-UK]

2014 iMac 27 5K - LM270QQ1 SD(A2) or A3
2015 - B1
2017 - C1
iMac Pro - D1
2019 - E1
2020 - F1

 

[fredn]

According to @Aiwi in post #822 in his Github link the R1811 is rated at providing 90w power in the System Information of his laptop.

The amount of PD seems to be limited by the power supply you are using. According to the manufacturer for the R1811 board, we need at least 24V 7.5A (180W) for 65W PD. When I added an extra 30W capacity by using a LRS-200-24 24V 8.8A (210W) power supply, it reported itself as being able to deliver 90W.

Interesting that it can PD up to 90W! I guess that picture from AliExpress is wrong.

Does anyone know where I can find the authoritative PDF/manual/datasheet of the R1811? Been looking for it without success.

 

[Regulus67]

I have only a pdf file, which show how to connect the cables correctly on the R1811 card.

But there is some information on StoneTaskin. Might be useful? Note it does say 65W fast charge. Probably what you have seen too

 

[PaulD-UK]

From page 16 of this thread, post #399 here is a download link to the pdf 'data sheet' of the CY-R1811 v3 board.
It's mostly in Chinese, and it's only of limited use, as there is no real info of the internal functions of the board.

 

[fredn]

From page 16 of this thread, post #399 here is a download link to the pdf 'data sheet' of the CY-R1811 v3 board.
It's mostly in Chinese, and it's only of limited use, as there is no real info of the internal functions of the board.

Thank you. That looks like it's for the V3 version of the board; I guess the V4 version of the board now allows up to 90W PD. I wonder what other changes were made?

A bit of googling did not turn up the V4 pdf unfortunately.

The manufacturer ChiYa Technology's website seems to be down also. Looking through the Wayback Machine, I can't even find a page for the R1811. Why can't they just do like every electronic manufacturer and have a proper website with downloadable manuals and materials? lol!

 

[PaulD-UK]

I think the only obvious change between v3 and v4 was the addition of a 12v power socket to supply the heatsink fan.
Of course there could be internal differences, but I doubt they changed the USB-C PD chip.
I think @Aiwi is correct - it CAN do 90 watts if the power supply is capable of the high amps needed, but the cooling on the board may not be able to cool the board when 5+ amps is flowing through it to supply 90 watts,
So they just spec it lower...

Chiya is the manufacturer of the board, but it's not 'their' product - i think it's a commissioned design and 'made to order' for other companies to sell it. So the sellers deal with the marketing (or lack of...)

 

[Aiwi]

I think the only obvious change between v3 and v4 was the addition of a 12v power socket to supply the heatsink fan.
Of course there could be internal differences, but I doubt they changed the USB-C PD chip.
I think @Aiwi is correct - it CAN do 90 watts if the power supply is capable of the high amps needed, but the cooling on the board may not be able to cool the board when 5+ amps is flowing through it to supply 90 watts,
So they just spec it lower...

Chiya is the manufacturer of the board, but it's not 'their' product - i think it's a commissioned design and 'made to order' for other companies to sell it. So the sellers deal with the marketing (or lack of...)

I don't know if USB-PD would introduce that much more heat? It's delivering 20V from its 24V source, and I bet the efficiency isn't terrible.

Regardless, I noticed that the heatsink for the driver board in my original design was too hot to touch after just a couple of hours of use. I did a small redesign and repurposed the original iMac fan together with a Noctua NA-FC1 PWN Fan controller. My driver board was flipped and now faces out towards the back vents.

My build page on GitHub is updated to reflect this change and the parts list is updated.

I found your old post about the pinout for the fan PaulD, but here's a picture for any other modders out there. Again, all of this can be found on the build page on GitHub.

It's not using the ducted airflow design like the original iMac, for now. I do believe we are at a different order of magnitude in terms of heat output on these monitor conversions compared to the original i7 7700K Radeon 580X iMacs we are replacing.

 

[fredn]

My build page on GitHub is updated to reflect this change and the parts list is updated.

Work of art. Amazing.

 

[fredn]

Regardless, I noticed that the heatsink for the driver board in my original design was too hot to touch after just a couple of hours of use. I did a small redesign and repurposed the original iMac fan together with a Noctua NA-FC1 PWN Fan controller. My driver board was flipped and now faces out towards the back vents.

Just to confirm, you are now using both the Noctua fan and the original iMac fan?

If so, how's the noise level?

 

[Aiwi]

Just to confirm, you are now using both the Noctua fan and the original iMac fan?

If so, how's the noise level?

Yes, they are both running.

I have been testing to run only the iMac fan and only the Noctua fan today. But with both of them on I can not really hear them. So I figured the extra cooling won't hurt.

If I hold my breath in my dead-silent home office I am actually able to hear a faint sound. But, it's a very non-obtrusive one. For a lack of a better reference, it sounds like the original iMac (2017 in my case) in its lowest speed setting.

 

[thewilewizzard]

Comrades, tell me, is it possible to increase the frame refresh rate on the matrix while lowering the resolution?

 

[PaulD-UK]

From the R1811 data sheet:
DP interface supports 5K@60HZ RGB 10BIT and 4K@144Hz.
HDMI interface supports HDMI 2.0 protocol and supports 4K@60Hz

 

[thewilewizzard]

From the R1811 data sheet:
5K@60HZ RGB 10BIT and 4K@144Hz.

did it work out on real experience? when selecting a 4k image, the interface on the top right writes 60 Hz. My version of displayport 2.1 and in theory should support

 

[PaulD-UK]

I haven't tried it.
I think TB4 Macs only support up to DP 2.0. (Anything over DP 1.3 should offer 4K 120/144Kz...)

 

[Aiwi]

Comrades, tell me, is it possible to increase the frame refresh rate on the matrix while lowering the resolution?

It is not possible to drive the iMac 5K panels beyond 60Hz at any resolution. That was really cool back in the day with CRT displays

The R1811 can be used with other panels, e.g. panels with 4K 144Hz like this one (please note, this is just an example and I have not verified that this specific panel works with the R1811).

 

[55filipp]

Certainly on the T18 I get 500nits without the extra current board… I now have an unused current board that I didn’t need 🤦🏻‍♂️

looking for T18/T19/R1811 for iMac 27 late 2014 👀

 

[jason3w]

I ordered the "cheap" JRY-W9CUHD-AA1 board. Arrived today and is working fine so far. Attached with only 1 USB-C Cable to my Macbook Air M1. Works straight, no settings needed
I ordered here: 27 '' iMac A1419 A2115 5K LCD Controller With DP Type-c Driver Board
Paid around €190 incl. shipment and import taxes
more details when finally mounted View attachment 2310350 View attachment 2310351

Nice! Can i ask what year iMac you have? I am looking at this board too, for the 2015 iMac. Cheers

 

[kevinherring]

Nice! Can i ask what year iMac you have? I am looking at this board too, for the 2015 iMac. Cheers

I used one of these boards (paid ~£130) on a 2015 iMac screen last week. Previously I have successfully used an R1811 version which was nearly twice the price. Notable differences between the two: No remote control, no fan on the heatsink, the OSD is different (red colour and in the bottom right corner of the screen). So overall I would recommend it, especially given how much cheaper it is!

 

[kevinherring]

I don't know if USB-PD would introduce that much more heat? It's delivering 20V from its 24V source, and I bet the efficiency isn't terrible.

Regardless, I noticed that the heatsink for the driver board in my original design was too hot to touch after just a couple of hours of use. I did a small redesign and repurposed the original iMac fan together with a Noctua NA-FC1 PWN Fan controller. My driver board was flipped and now faces out towards the back vents.

My build page on GitHub is updated to reflect this change and the parts list is updated.

I found your old post about the pinout for the fan PaulD, but here's a picture for any other modders out there. Again, all of this can be found on the build page on GitHub.

It's not using the ducted airflow design like the original iMac, for now. I do believe we are at a different order of magnitude in terms of heat output on these monitor conversions compared to the original i7 7700K Radeon 580X iMacs we are replacing.

<snip>
Nice work with the perspex.

Do you get much PSU squeal from the Mean Well LRS-200-24 when there is no load (i.e. the screen is in power saving mode)? I had to use a latching switch to kill the power completely as it would drive me mad.

How do the USB-C and DP cables leave the chassis at the back/bottom? I can't make it out.

 

[Aiwi]

<snip>
Nice work with the perspex.

Do you get much PSU squeal from the Mean Well LRS-200-24 when there is no load (i.e. the screen is in power saving mode)? I had to use a latching switch to kill the power completely as it would drive me mad.

How do the USB-C and DP cables leave the chassis at the back/bottom? I can't make it out.

Thanks!

I do not have any PSU squeal at all.

The USB-C and Displayport are both converted to USB C receptacles and placed in the original Thunderbolt 3 location. See Chapter 5. Modifications. I use regular USB C cables between the source and the iMac.

Here's an example of a Macbook connected with USB C to the iMac. (the ethernet cable is also connected)

 

[caiosimonbreda]

I ordered the "cheap" JRY-W9CUHD-AA1 board. Arrived today and is working fine so far. Attached with only 1 USB-C Cable to my Macbook Air M1. Works straight, no settings needed
I ordered here: 27 '' iMac A1419 A2115 5K LCD Controller With DP Type-c Driver Board
Paid around €190 incl. shipment and import taxes
more details when finally mounted

Hey, is your board still doing okay? A couple of reviews on Aliexpress say it stopped working really quickly.

 

[tehotaone]

I know this will be perceived lazy by some, and I know where the search function is I am just hoping to get the advice from someone to say what the best conversion board for a 2017 A1419 5k seems to be ? I have a new M2 Studio Ultra and want to use one cable if possible to drive my 5k iMac. I only need 5k monitor functions, I don't need charging, speakers, webcam none of that, just full res, bit depth and brightness. Can someone weigh in with the current suggestions and maybe a vendor? I would really appreciate your advice and or experience. Thank you.

 

[Benelb]

Thanks to everybody giving advice in this thread. I also converted my iMac in late 2015.
I went via this forum to a Haijing Cool T18. Ordered via the link.
Installation went smoothly and works perfectly.
I soldered the original on/off button to the T18 circuit board and this also works.
However, I am running into one problem.
Would like to use the original iMac speakers.
The T18 board also has a Pam8006A amplifier and a speaker connection with L-, L+, R- and R+
I ordered the Treble Bass Speaker Crossover Divider for iMac on Ali
Connected this but get no sound.
At this moment I have connected the original speakers with a separate Pam8610 amplifier and 3.5 audio jack.
But then I continue to have a very light noise over the speakers.

Question: the T18 driver board contains a Pam8006A amplifier. Does anyone know how I can use this?