DIY 5k Monitor - success :-)

[yaosiang]

yes I can confirm that. see the TB3 port is activated.

while you succeed on R1811 with single USB-C cable & DP cable, I can see you have a dedicated NVIDIA graphic card (which means you have a desktop PC?)

It was a laptop with dedicated built-in NVIDIA graphics card. In Windows, no devices was shown as connected under Thunderbolt Port 1 and 2 when the laptop was connected to the DP input on the R1811 via USB-C to DP.

The LG UltraFine 5K uses two tiles of 2560x2880 so do you think it works with your laptop because each tile is lower than the 4096px max limit?

 

[priva28]

Just to set expectations - the sound coming out of an iMac isn't just speakers with an amplifier. It's speakers with an amplifier driven by a DSP designed and tuned to compensate for the frequency response characteristics of the system.

Oh interesting, that definitely makes sense. Thanks for the heads up. I wanted something similar but it really isn't a big deal if I can't get it perfect. As long as I can like watch a YT video or have other random system sounds come through it should be fine. I'm guessing without the DSP, it'd probably still be better than most speakers built into monitors anyways haha.

FWIW I too bought a cheap TPA3116 amplifier, but the sound was worse than using the inbuilt audio power amplifier in the R1811, and I think the R9A18 board has the same circuitry for audio output.

I guess in this case I might just try the built in amp to the R9A18 first. The less components inside the case means less that can go wrong! I'll probably try both eventually out of curiosity though. Anyone have any good curves that they've used with eqMac to get decent results?

Another thing I'm kind of curious about is the R9A18 (and the others like R1811) seem to have 3 DP connections. I have a base M2 Mac Mini I'm using as a home server, but it'd be nice to connect it to this display too for quick tasks when my MacBook isn't connected. On the board, the ports are labelled DP, DP1, DP2. But I've also seen the first "DP" port referred to as "MST" online.

Will it work for DP1 & DP2 going into a dual DP to thunderbolt adapter into my MacBook for full 5K 60hz 10bit and the last DP going into my Mac Mini with just a DP to USB-C cable? I'm guessing I might be able to get 5K 60hz but at 8bit colour or YUV instead of RGB (which isn't a big deal for the Mac Mini). Also guessing auto switching probably wouldn't work (though I recall seeing someone using a Pi Zero to digitally switch it through the HDMI port). I guess I need to stop guessing and just start trying things out . Excited!

 

[priva28]

Anyone try a cheaper dual DP adapter?

I've found one that seems to be less than half the price of the StarTech one people report as working:

https://www.scorptec.com.au/product/cables-&-adapters/usb/100126-vl-uc2dp

 

[JavD]

The LG UltraFine 5K uses two tiles of 2560x2880 so do you think it works with your laptop because each tile is lower than the 4096px max limit?

No. As my photo indicated, TB3 has activated for both ends, i.e. sufficient bandwidth. LG Ultrafine 5K is Apple accredited TB3 display and AFAIK its has its own integrated TB3 interface/socket to communicate with (macOS/Win) TB3 devices. That's why M1 with single USB-C cable(none TB3 cable) cannot reach 5K with Ultrafine 5K. i.e. not using TB3 protocol but DSC if connected to DP1.4 port.

then I have another thought also as @davidg5678 mentioned about DSC video protocol and @i486dx2-66 mentioned about Dual-DP_to_USB-C, I am thinking what if I bought something like this : a TB3_to_Dual-DP(1.4) adaptor, and connecting the TB3 to my PC(X1 Carbon 2018), while TB3 port activated, it should be delivering 5K signal to the DP1.4 port and if I use one DP1.4 to connect the driver board T18 on the DP1.4, would it reach 5K?

or even simpler, if there is a TB3 cable with TB3 chip embed on one end, and the other end is DP1.4?

 

[priva28]

the last DP going into my Mac Mini with just a DP to USB-C cable

Nope! Doesn't work. That port must be reserved for MST. What do you guys think the best way to handle switching between multiple computers would be without a bunch of cable swapping? I guess I can probably settle for 4K over HDMI for the Mac Mini.

Anyways, yet another success with the R9A18 except for a few issues! I'm using a single DP to USB-C thunderbolt cable to connect the screen to my MacBook Pro and it runs just fine at 5K 60hz, but in YUV mode. I'll purchase the dual adapter soon.

Though I seem to be having an issue where the backlight control is locked. Setting it from 0-100 has absolutely no difference. I've tried swapping between the 2 backlight connectors on the board and there's no difference. FWIW I have the R9A18 V1.1 with V05 installed. Also tried resetting. Anyone else with this issue?

 

[davidg5678]

I am thinking what if I bought something like this : a TB3_to_Dual-DP(1.4) adaptor, and connecting the TB3 to my PC(X1 Carbon 2018), while TB3 port activated, it should be delivering 5K signal to the DP1.4 port and if I use one DP1.4 to connect the driver board T18 on the DP1.4, would it reach 5K?

Since we know Thunderbolt 3 can handle the extra bandwidth required for 5K without DSC, (as shown by the LG Ultrafine that works with your laptop) it would to me make sense if using this adapter works.

Startech's website says this adapter is compatible with the Thinkpad X1 Carbon. You'd need a DP1.4 cable to plug between the T18 and the Startech. You'd also need to select DP1.4 in the menu of the T18 if it isn't already selected.

I think this is definitely worth a try to see if it works. Just make sure wherever you buy it from accepts returns in case the product ends up being the wrong one.

 

[yaosiang]

No. As my photo indicated, TB3 has activated for both ends, i.e. sufficient bandwidth. LG Ultrafine 5K is Apple accredited TB3 display and AFAIK its has its own integrated TB3 interface/socket to communicate with (macOS/Win) TB3 devices. That's why M1 with single USB-C cable(none TB3 cable) cannot reach 5K with Ultrafine 5K. i.e. not using TB3 protocol but DSC if connected to DP1.4 port.

then I have another thought also as @davidg5678 mentioned about DSC video protocol and @i486dx2-66 mentioned about Dual-DP_to_USB-C, I am thinking what if I bought something like this : a TB3_to_Dual-DP(1.4) adaptor, and connecting the TB3 to my PC(X1 Carbon 2018), while TB3 port activated, it should be delivering 5K signal to the DP1.4 port and if I use one DP1.4 to connect the driver board T18 on the DP1.4, would it reach 5K?

or even simpler, if there is a TB3 cable with TB3 chip embed on one end, and the other end is DP1.4?

I understand the issue that you are facing now. What you are effectively saying is that your laptop needs to output in TB3 mode so there is sufficient bandwidth for 5K@60Hz.

The USB-C DP Alt Mode on the X1 Carbon Gen 6 only supports DP 1.2 (according to here). This explains why you are only getting 4K@60Hz at the moment.

The LG UltraFine 5K has a TB3 to dual DP 1.2 or equivalent adapter built into the monitor. The USB-C port on your laptop operates in TB3 mode when you connect the monitor to your laptop. TB3 has sufficient bandwidth for 5K60Hz (or dual 2560x2880@60Hz in the case of UltraFine 5K). This explains why you are getting 5K@60Hz with the LG.

The T18 does not support TB3 so you are stuck with 4K@60Hz at the moment. I agree with @davidg5678 that your idea of using a TB3 to dual DP 1.4 adapter (utilising only 1 DP port to connect to the T18) might actually solve the problem if the adapter activates the TB3 mode on your laptop.

Assuming the connection between your laptop and the T18 is via DP 1.2 (in USB-C DP Alt Mode), you should be able to operate the T18 at 5K@30Hz by creating a custom resolution. I have successfully run the R9A18 at 5K@46Hz via single DP 1.2. Have you tried this yet?

I am not sure if the issue with Intel/Lenovo revoking 5K support on the X1 Carbon Gen 6 is genuine or has been resolved but it is worth confirming that your laptop can output 5K resolution before going any further to avoid further disappointment.

 

[tcapanema]

Hi! After my iMac 2017 (21.5") died I decided to convert it into a 4K monitor. I bought this driver board for the LM215UH1-SDB1 panel (CY.R9516 V1) and it arrived yesterday.

The first challenge was to remove the AC inlet to use the only hole available in the 21.5" chassis to pass the cables. I haven't found any written or video tutorial on how to do that. The AC inlet is glue sticked in the chassis and I've used some grip pliers to remove it with brute force. Another possible option would be to use a heat gun on it to try to melt the glue before removing it.

AC inlet from 21.5" iMac 2017 removed with grip pliers

I passed the OSD control panel through the AC inlet hole and fixed it with two screws using the iMac original external ports

I also fixed the driver board in the iMac case using only one screw. This is how it looks like:

Question 1: Now I have some questions. First, anyone knows if it's possible to connect and make the original speakers work? The 21.5" speakers connectors are different from the 4-pin connectors in the 27" version. It's a 6-pin connector, I guess. It looks like this:

I wonder if there's an adaptor for this. This is a pic of the board:

Question 2: When I first connected all cables just to test the display, I had access to the OSD settings via the OSD control panel (Picture, Display, Color etc):

But after assembling everything together only two buttons are working in the OSD panel (on/off and the display selector).I lost access to the settings and I'm not sure what happened. Nothing happens after pressing the first three buttons:

Question 3: There's a lot of backlight bleed in the screen. Anyone had this issue? Are there any possible solutions for that?

Backlight bleed in iMac 2017 21.5" monitor panel

Any feedback will be greatly appreciated. Thanks!

 

[digitalrelay]

Maybe your OSD control panel is shorting out on the chassis. I’d try pulling it off and see if you get control back.

I’m not sure on the other stuff. You could send an audio source to those pins on the speakers and create your own pin out for what goes where. Just be sure to figure out phase if you do it this way.

 

[PaulD-UK]

WRT your Question 1, on Page 16 of this thread, post #380, is the pinout of the 27" iMac speakers:

https://forums.macrumors.com/threads/diy-5k-monitor-success.2253100/page-16?post=31844716#post-31844716

In your picture it isn't clear if pins 3 and 4 are looped back like they are on the 27" speakers that have 6 pin connectors.

 

[tcapanema]

Maybe your OSD control panel is shorting out on the chassis. I’d try pulling it off and see if you get control back.

I’m not sure on the other stuff. You could send an audio source to those pins on the speakers and create your own pin out for what goes where. Just be sure to figure out phase if you do it this way.

Thanks! You were right and I was wondering just that... the OSD control panel was shorting in the chassis... the menu is fully working now. I changed some settings, Backlight to 100, FreeSync On etc. I thought that after changing the Backlight setting the backlight bleed would be less noticeable, but that's not the case... it's still very visible on a white background and it's bothering me.

 

[yaosiang]

Question 1: Now I have some questions. First, anyone knows if it's possible to connect and make the original speakers work? The 21.5" speakers connectors are different from the 4-pin connectors in the 27" version. It's a 6-pin connector, I guess. It looks like this:

View attachment 2232796

The connector looks similar to the 27" A1419 iMac. Pin out as below:

For each side, you have: Woofer Positive (Pin 1), Woofer Negative (Pin 2), Tweeter Positive (Pin 5), Tweeter Negative (Pin 6).

I suggest you label each individual wire before cutting off the connector. You can pull the wire out from the connector by pushing down on the the gold crimp in the photo if you choose not to cut the cable.

Apple uses Molex Pico Lock series for the speakers. Pin 1 can be identified using the triangle indicator mark on the connector (drawing):

I will try to look for a higher resolution image of the R9516 driver board and show you the connections between the speakers and the driver board.

 

[PaulD-UK]

This is the R1811's audio sockets next to the CSC3110 audio amp chip.
Have a look and see if your R9516 board is the same - it looks as if it is from your pic above.
From top to bottom the speaker output pins are L+, L-, R-, R+.

 

[tcapanema]

This is the LEFT speaker pin connector from the iMac 2017 21.5", front and back

This is the RIGHT speaker pin connector, front and back

 

[PaulD-UK]

From left to right in your front pics of both speakers (with the contacts facing you):
1. Woofer +
2. Woofer -
3. ID link + connected to
4. ID link -
5. Tweeter +
6. Tweeter -

As to your backlight bleed, we can't see the connection where the R9516's backlight red/black cables are plugged into your monitors backlight ribbon cable.
Have you checked everything is making a good connection there?
If not, you backlight would be patchy, not uniform with edge bleeding.

 

[yaosiang]

It does look similar to the R1811 audio amplifier chip which is CSC3110.

The diagram below shows how I connected the speakers to the driver board. I combined both positives and both negatives for woofer and tweeter. Probably not technically correct (as it should go through some soft of filter) but the speakers work and sound acceptable.

Please remember to set the volume to 5% on the OSD before you attempt to test the speakers as it gets very loud even at 25% only.

For reference, the image below shows the connector for the R1811/R9516 speakers (link):

The driver board uses JST PH series for the speaker connector.

 

[tcapanema]

A photo of my board (BK-R9516 V1)

The CSC3110 audio amp chip:

In the back of the board I can see the Left and Right scheme for the speakers:

 

[PaulD-UK]

I've tested my speaker output and that marking is definitely WRONG. It should be L+ L- R- R+.

The data sheet confirms this (pin 23 and pin 20 of @yaosiang's diagram):

CSC3110 JunYi Datasheet, Features and Benefits, Stock and Price

JunYi CSC3110 Filter-free Class-D audio power amplifier - Download Datasheet.

datasheetspdf.com

@yaosiang By connecting the speaker tweeter/woofer in parallel you are presenting a 2 ohm load to each channel of the CSC3110 chip.
Its Data Sheet lists a minimum output load of 3.2 ohm, so the chip will be overdriven somewhat...

To be realistic I think the R1811 only drives the CSC3110 with a PVCC of 12 volts as its adjacent to the 12v fan connection, so the overload on the chip maybe won't be so bad for it. Hopefully.

 

[yaosiang]

This is the LEFT speaker pin connector from the iMac 2017 21.5", front and back

View attachment 2232947


This is the RIGHT speaker pin connector, front and back

View attachment 2232952

Look for the triangle circled in yellow:

Left:

Right:

 

[yaosiang]

I've tested my speaker output and that marking is definitely WRONG. It should be L+ L- R- R+.
The data sheet confirms this:

CSC3110 JunYi Datasheet, Features and Benefits, Stock and Price

JunYi CSC3110 Filter-free Class-D audio power amplifier - Download Datasheet.

datasheetspdf.com

@yaosiang By connecting the speaker tweeter/woofer in parallel you are presenting a 2 ohm load to each channel of the CSC3110 chip.
Its Data Sheet lists a minimum output load of 3.2 ohm, so the chip will be overdriven somewhat...

View attachment 2232983

Thanks @PaulD-UK. Does that mean I should only connect Tweeter Positive and Negative to the driver board and leave the Woofer Positive and Negative not connected?

Yes I agree that the silkscreen label on the PCB is wrong.

 

[PaulD-UK]

The woofer is the principle loudspeaker driver so that is the one to favour.

To do it properly put a 10 microfarad polypropylene audio capacitor in series with each tweeter, and a 0.15 millihenry inductor in series with each woofer.

A simpler fix would be to connect the woofer directly but put a 12 ohm audio resistor in series with the tweeter.
That would present 3.2 ohms to the amp, and you could boost the treble a bit to compensate for the lower output of the tweeter. Haha...

@yaosiang Are you from Kangleipak?

 

[yaosiang]

The woofer is the principle loudspeaker driver so that is the one to favour.

To do it properly put a 10 microfarad polypropylene audio capacitor in series with each tweeter, and a 0.15 millihenry inductor in series with each woofer.

A simpler fix would be to connect the woofer directly but put a 12 ohm audio resistor in series with the tweeter.
That would present 3.2 ohms to the amp, and you could boost the treble a bit to compensate for the lower output of the tweeter. Haha...

@yaosiang Are you from Kangleipak?

Thanks it sounds a little complicated but I might try it one day if I can get my head around it.

Nope, I am not from Kangleipak.

 

[tcapanema]

@PaulD-UK Thank you so much for your help! Regarding the backlight bleed, the red/black cables connection seems to be ok. I guess there's nothing much to do to try to solve this problem.

 

[vakman]

Hi All,

There are some awesome looking conversions here.

I have a 2017 iMac with the 5k panel and hoping to make the same mods

Here's my understanding for some of the boards available which will work.

1. R9A18 V1: Only supports DP1.2
2. R9A18 V2: Support DP1.4
3. R1811 V3 + V4: Supports DP1.4 and USB-C.
4. T18: Supports 5k @60HZ (single DP port can support 5K resolution) Type-c port, supporting audio + video + PD 65W reverse charging

Now, I came across another board on Alibaba called the Haijing T19, which claims 5k, with DP 1.4 and more importantly HDMI2.1 and works with the standard iMac LM270QQ1.

https://www.aliexpress.com/i/1005004451833256.html?gatewayAdapt=Msite2Pc

Question: Could this be a newer board and maybe something newer than the current favourite R1811? I'm planning to use this with a Mac Mini M2 Pro or possibly the Mac Studio M2 Max

Areas of concern:

1. Does it have USB-C
2. Can I hook up some speakers

Thanks all.

 

[tcapanema]

I guess I just burned my board somehow and I can't turn the monitor on no more.
I misconnected the red/black cables connection like that and plugged the power adapter.

The monitor didn't turn on. I noticed that the power adapter LED light was blinking, and thought I had an issue with my power socket so I tried in two different ones before opening the case and checking for the connections. Now, after connecting it properly, the power adapter LED light keeps blinking. When I unplug the power from the board the LED stays on as it should.


Video of the issue

There was no burning smell or anything... but it doesn't turn on anymore.
Is there anything I could try here? 😩