DIY 5k Monitor - success :-)

[baggiero]

I've started getting some "flashes" of black rectangles in random different areas of the screen this morning - and the whole screen has turned off and come back a couple of seconds later too (with OSD of connection info). Any advice from the collective on what might be afoot?
Screen isn't hot (has only been on via the button for 10s of minutes but the PSU has been powered up overnight (oops)).
[update] Turned it fully off at wall for a minute or two and it seems not to be doing it any more. Doesn't fill me with confidence though ...

 

[Aiwi]

You don't mean the hub but the distributor where you removed the port housings?


Ah ok, so you just soldered the 5V power supply in between?
So from the 24V power supply down to 5V with the converter and then use that to operate the 5V power supply. Then the ports are controlled with plus?

///Edit: Sorry for the confusion.

I mean you have two hubs here. You take one for the connections at the back but for what the other and how did you connect the additional short USB cables for the additional 5V power?

View attachment 2407468
Sorry again for the many questions and the bad English 🙈

I think I also forgot about how I did it. Now I can remember:

R1811 USB port #1:
- USB 3 Hub
+ Internal USB camera
+ Internal microphone
+ Internal ethernet card

R1811 USB port #2:
- USB 2 hub
+ 4 external USB ports

Yes, the 24V-5V DCDC has 5V connected with Y-shaped USB-cable you listed last in the list.

 

[PaulD-UK]

@baggiero screen flashes and short blackouts are an indication of low voltage from the PSU.
The Amazon reviews of what seems to be your PSU have some reports of less than the rated power output.
If it’s an LED driver it’s designed for constant current output rather than constant voltage, but I can’t find a data sheet to check the output characteristics.
The output voltage may have dropped after being on a long time.

 

[usert888]

Does anyone have the specs of the main chip on the R1811? I want to know what the maximum working temperature is. I've ordered a 80x80m10mm fan and PWM temperature controller, but to set it up correctly would like to know what a safe temperature is.

This is still a prototype, not the correct fan (this one is 80x80x20mm)

I was thinking to use 35°C (Tu in the picture) as the lower threshold (which means the fan will run minimum speed until this threshold is reached, then will increase the speed linearly) and a temperature 'width' of 25°C (Td in the picture), so the max temperature is 60°C before the fan blows at full speed. I will connect the fan controller on the existing fan header, so it also uses the board's logic before the fan kicks in.

Reason behind the bigger fan is that bigger fans can run slower for the same airflow, meaning less noise.

 

[PaulD-UK]

It’s a Realtek RTD2718Q, but it’s data sheet seems to be marked ‘restricted to manufacturers’.

However StoneTaskin (ISTR) said to a previous poster in this thread that the heatsink should not exceed 65 degrees C.

I set my original heatsink fan the same as you propose, ramping from 35 degrees to max at 55.
I’ve had absolutely no problems for the 16 months since I built my R1811 monitor. 👍

I’ve never heard my fan, and I don’t think it speeds up very much.
Your fan is much bigger…
But I don’t power a laptop from the R1811.

 

[usert888]

It’s a Realtek RTD2718Q, but it’s data sheet seems to be marked ‘restricted to manufacturers’.

However StoneTaskin (ISTR) said to a previous poster in this thread that the heatsink should not exceed 65 degrees C.

I set my original heatsink fan the same as you propose, ramping from 35 degrees to max at 55.
I’ve had absolutely no problems for the 16 months since I built my R1811 monitor. 👍

I’ve never heard my fan, and I don’t think it speeds up very much.
Your fan is much bigger…
But I don’t power a laptop from the R1811.

I do plan to power a laptop. I'm not sure what the logic on the R1811 exactly is, but the standard fan kicks in when USB-C is powering a laptop, could be temperature triggered, could be hardwired like if USB-C supplies power. That will be kept unchanged, but I hope I can keep the fan noise down when it does kick.

Thanks for the info, well appreciated.

 

[drdot]

I was also able to turn an old iMac 27 late 2015 into a monitor.
I used the jry-w9cuhd-aa1 board from aliexpress. I also am powering the stock speakers with a crossover plugged directly into the board. All in all its awesome. But i want to make it a cleaner appearance.
So currently im stuck at the power supply.
The seller states that the board needs 24v for PD-Charging.
So i bought a Power Supply which outputs 24v 8.3a max. This should be sufficient for everything.
But when everything is wired up and i plug the Barrel connector into the board, nothing happens.
So i measured everything and the power supply outputs constant 24v at the barrel jack connector.
But everytime it gets plugged in the voltage drops immediately to under 1v.
Has anybody run into the same problem?
Does the board take 24v or not?
With a 12v6a power supply there is no problem powering the board.

 

[T-Bone90]

@Aiwi Thank you for the explanation!

But I haven’t really understood how to connect the short usb cables with the additional power source.

If I have seen it correctly, you have removed the housing from the 4 Ports. The hub is connected to one of the USB ports on the R1811.

Now I wonder how the USB CABLE with the extra power have to be connected here? How are these sandwiched? Does the cable need to be taken apart?

Do I really need the extra power? And could the 5V converter also be a 3A or 8A or is that not possible?

Thank you very much.

 

[Edge]

I was also able to turn an old iMac 27 late 2015 into a monitor.
I used the jry-w9cuhd-aa1 board from aliexpress. I also am powering the stock speakers with a crossover plugged directly into the board. All in all its awesome. But i want to make it a cleaner appearance.
So currently im stuck at the power supply.
The seller states that the board needs 24v for PD-Charging.
So i bought a Power Supply which outputs 24v 8.3a max. This should be sufficient for everything.
But when everything is wired up and i plug the Barrel connector into the board, nothing happens.
So i measured everything and the power supply outputs constant 24v at the barrel jack connector.
But everytime it gets plugged in the voltage drops immediately to under 1v.
Has anybody run into the same problem?
Does the board take 24v or not?
With a 12v6a power supply there is no problem powering the board.

StoneTaskin offer a 24V supply bundled with the JRY-AA1, so 24V should work. (Mine is running on 12V.)

I would check the barrel connector polarity, and the fit (e.g. does it go in all the way, is it 5.5*2.5mm.)

 

[Aiwi]

@Aiwi Thank you for the explanation!

But I haven’t really understood how to connect the short usb cables with the additional power source.

View attachment 2407837

If I have seen it correctly, you have removed the housing from the 4 Ports. The hub is connected to one of the USB ports on the R1811.

Now I wonder how the USB CABLE with the extra power have to be connected here? How are these sandwiched? Does the cable need to be taken apart?

Do I really need the extra power? And could the 5V converter also be a 3A or 8A or is that not possible?

Thank you very much.

Maybe this diagram helps?

3A will give you 750mA per USB port if they are all drawing power. 500mA is enough according to the USB standard.

However, if you want to charge something quickly, up to 1500mA may be pulled. So, if you charge 4 iPads at the same time, you could need 6A. This is not very likely, so you can save some money and buy 3A.

 

[T-Bone90]

Ah cool thanks for the diagram.

So you use one of the „USB Cable with Additional Power Source“ put it in the board, the second port comes to the 5V converter and the end of the cable in the 4x Switch?
Have you cut off the usb port (side to 5V Converter) and solder the cables to the 5V Converter?

 

[Aiwi]

Ah cool thanks for the diagram.

So you use one of the „USB Cable with Additional Power Source“ put it in the board, the second port comes to the 5V converter and the end of the cable in the 4x Switch?
Have you cut off the usb port (side to 5V Converter) and solder the cables to the 5V Converter?

Yes

 

[T-Bone90]

Perfect I have a DC Converter 24V-5V 5A, I think this is enough. It's not planned that I'll load anything with all four connections anyway. That's why I have my TB Dock. To be honest, I'm not sure if it makes any sense to install the connections. But whatever, now I've ordered everything.

Now I just have to see how I can connect the converter to the power supply. I assume that I go out of the large power supply with -V and +V and then into the converter with plus and minus.

 

[PaulD-UK]

The MeanWell LRS-100-24 has two 24v outputs so you connect one to the R1811 and the second to the 24-5v converter.

 

[usert888]

I'm finalizing my three builds. I'm at revision 7 for the 80x80x10mm fan mount because I needed every single mm to make it fit and not touch the case. The STLs for it can be found at https://www.printables.com/model/968024-diy-imac-late-2014-5k-monitor-kit-for-r1811-driver

 

[fhall1]

Is it worth having that huge, "thick" fan if it is almost touching the case? With it that close to the case your airflow is probably greatly restricted. Instead of 10mm, maybe something 5mm to 8 mm would be better?

 

[PaulD-UK]

Having a VESA mount iMac helps, as if the hinge spring is absent there is quite a bit more room, and the fan is drawing air into the R1811 through the vents, so there shouldn't be a starvation of incoming air.
Where the rising hot air exhausts from is another matter, but there's a lot of aluminium in the case, which helps...

My screen doesn't get hot at all, so mounting the R1811 on a 3D printed plate again the back of the screen panel seems a good solution, if the R1811 is cooled.

 

[usert888]

Is it worth having that huge, "thick" fan if it is almost touching the case? With it that close to the case your airflow is probably greatly restricted. Instead of 10mm, maybe something 5mm to 8 mm would be better?

The fan is positioned at the vents in the case. There is a 2-3mm margin between the case and the silicon fan mounts. Those are 2mm thick, so 4-5 mm total margin between fan and case.

I think it will be fine.

 

[usert888]

Having a VESA mount iMac helps, as if the hinge spring is absent there is quite a bit more room, and the fan is drawing air into the R1811 through the vents, so there shouldn't be a starvation of incoming air.
Where the rising hot air exhausts from is another matter, but there's a lot of aluminium in the case, which helps...

My screen doesn't get hot at all, so mounting the R1811 on a 3D printed plate again the back of the screen panel seems a good solution, if the R1811 is cooled.

Mounting the boards to the panel turned out to be a good choice. It made it easy to work on and connect everything. And when mounting the screen in the case only two cables need to be connected: the speakers and monitor control panel.

Also the angle to the R1811 board is great to connect cables.

 

[T-Bone90]

@usert888 Did you only glue the board with the self-adhesive mat that was already on the back of the Board?
It is not so wrong to mount the board on the Display side. I would definitely like to get to the connections through the RAM opening and otherwise I would have to make a holder.
Hmm it‘s a idea

 

[usert888]

@usert888 Did you only glue the board with the self-adhesive mat that was already on the back of the Board?
It is not so wrong to mount the board on the Display side. I would definitely like to get to the connections through the RAM opening and otherwise I would have to make a holder.
Hmm it‘s a idea

I printed brackets. The board is screwed onto the brackets and I used double adhesive foam tape to mount the brackets to the case.

In retrospect I think the foam tape helps reducing vibrations from the fan. Together with the silicon fan mounts and printed gasket in TPU.

 

[T-Bone90]

I printed brackets. The board is screwed onto the brackets and I used double adhesive foam tape to mount the brackets to the case.

Ah you mean the "R1811_board_mount.stl"? That looks nice. I think I will print this and also for the crossover boards.

Have you even removed the WLAN antennas? And what about the thin cables for Bluetooth etc? The four...a cable goes into the back Apple logo. Remove everything or doesn't bother you?

 

[T-Bone90]

Hello everyone,

does anybody have a recommendation for a good power supply from the EU?

The MeanWell from post #1,696 has extreme coil beeping and will be sent back.

 

[PaulD-UK]

That’s a pity. Maybe all the cheaper PSUs are encapsulated to prevent this.
My PSU is open but filled with hard setting thermal paste, probably for this reason.

Another issue is something called Power Factor Correction.
The nearer to 1 (or 100%) it is the better. If the PFC is 0.5 then the waveform of the current flow in the PSU is more like a square wave, not a smooth sine wave, so the current in the transformer coils is rapidly switching on and off.
This makes the noise.

A good PFC is 0.9 or more, and the circuitry in the PSU data sheet is called Active PFC.

 

[T-Bone90]

Thank you. I am now testing the Dehner Elektronik SPB 100-24. That's supposed to be pretty good too. Let's see.

Another question about VESA. I can buy a VESA hinge on Ebay for a 2017 iMac. But did I understand correctly that there is no mount kit for the outside, which can be bought at a good price? So the VESA hinge is of no use to me?