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kevinherring

macrumors newbie
Oct 30, 2006
15
3
Although your question refers to a poster who has used the internal iMac 12V 300W supply with an RA918, I can confirm that the JRY board advertises itself as a 27W charger (I assume 9.0V@3A) when powered by an external 12V supply (in my case a 72W 12V@6A supply) and connected via a single USB-C cable to a Macbook Pro M1.
Interesting... But does that 9v actually achieve anything? I assume it still doesn't charge the laptop, but it could perhaps power the laptop's USB ports?
 

sadontsev

macrumors newbie
Apr 21, 2024
14
4
Interesting... But does that 9v actually achieve anything? I assume it still doesn't charge the laptop, but it could perhaps power the laptop's USB ports?
I can confirm that the JRY draws about 27-30W additional power from the socket to charge the Mac (it also charges iPhone 15 Pro when connected) when connected via USB 3 cable.
The Mac shows that it receives 27W in the Power section of the System Report.

That could be good enough for casual usage with the M Pro Macs.
I see that under a not-heavy load, the Mac draws under 20W for me (while browsing, 75% brightness).
But it can peak 50W under load (ie video encoding) that would start drawing the battery charge.
 
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Edge

macrumors regular
Jul 28, 2005
132
26
Interesting... But does that 9v actually achieve anything? I assume it still doesn't charge the laptop, but it could perhaps power the laptop's USB ports?
Obviously that depends on the connected laptop — the primary factor is the power draw, which will differ between users — and the reliability and accuracy of the power supply in question.

In the case of my Macbook Pro M1, I have previously had it attached to a 30W charger. It obviously does not charge while using the laptop, and can drain the battery with heavier use, but will slowly charge when sleeping. At this stage I'm not super keen to test my laptop at length charging with the JRY/5K set-up, even though my 72W external supply is Belkin-branded and should be accurately rated and reliable enough.*

I imagine it does not continue to charge when the JRY is switched off via the control board, but perhaps @sadontsev can comment on whether the laptop charges when the JRY board is in power-save mode (with the red light glowing on the control board)?

*Edit: case in point, I just touched the jerry-rigged 12V 5.5x2.5 barrel connector extension I have running outside the 5K iMac case, and the whole thing switched off instantly due to a dodgy connection in the temporary screw terminals I used.
 
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Edge

macrumors regular
Jul 28, 2005
132
26
*Edit: case in point, I just touched the jerry-rigged 12V 5.5x2.5 barrel connector extension I have running outside the 5K iMac case, and the whole thing switched off instantly due to a dodgy connection in the temporary screw terminals I used.

Re: using the existing iMac 300W 12V power supply for the JRY board

I have ordered the following cable to connect to the Delta 300W 12-pin power supply cable. Hopefully it is the correct pitch, as the description appears to fit (even though the photos aren't accurate, they show a 10-pin.)


I am about to remove the screen on my 5k display once again, as my temporary 12V wiring appears to have been completely inadequate. (I hope I haven't shorted anything.)

Hi, unlike the R1811, I don't think there is a source of simple 12v power from the JRY board.
Only the USB PD supply out of the USB-C port - which isn't a good idea to fiddle with without proper expertise.

The USB PD shouldn't be outputting 12V as it's not part of the spec, which I think you mentioned earlier? Perhaps because it is rarely if ever used as a charging voltage?

There may be 12v on the DC_In/Gnd pins on the 10 pin alternative power-in socket at the top of the board, next to the eDP connector. But if there is this may not be switched? You would need to test that to find out if you could use that...

I will attempt to test this for 12V fan power once my iMac is open again (blue painters tape to the rescue) .

In addition, hopefully the pads in this DC-In location are adequately sized to solder the 12v power from the 300W OEM power supply.
 

PaulD-UK

macrumors 6502a
Oct 23, 2009
576
268
Apple has used Molex Micro-Fit 3.0 connectors for all its iMac variant,
2-pin (iMac Pro input, iMac 21 2012+ input), 3-pin (iMac 27 2012+ input), 6-pin (iMac 21 2012+ output) and 10-pin (iMac 27 2012+ output).
iMac speakers use Molex Pico-Lock plugs/sockets.

"12v on the DC_In/Gnd pins on the 10 pin alternative power-in socket at the top of the board..."
Quote: "...hopefully the pads in this DC-In location are adequately sized to solder the 12v power from the 300W OEM power supply."

If you want to solder your 12v supply to the board use the 4 pin solder pads, marked DC_In ++-- , next to the barrel socket input.
I think the 10 pin socket may only be suitable for power input if you connect ALL the 12v, 5v and StandBy 5v supplies etc?
But it may supply 12v out to power a fan?
 
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sadontsev

macrumors newbie
Apr 21, 2024
14
4
I imagine it does not continue to charge when the JRY is switched off via the control board, but perhaps @sadontsev can comment on whether the laptop charges when the JRY board is in power-save mode (with the red light glowing on the control board)?

I believe the answer is yes
Silly me testing it first with the fully charged laptop.

I see 40W being drawn by the display when the laptop and the display are in sleep (power saving) modes. But the laptop is not fully charged.

Disclaimer: I'm talking about Power saving, not turning off the display via the power button.

When I was testing it with the fully charged laptop, I saw the display drawing about 20-25W still, which is more than it does being in Power saving but the laptop is being connected to the MagSafe charger as well.
I think it still does something to maintain the laptop functions.

Which sounds great.

However, personally, I wouldn't trust my laptop power management to the JRY and an old iMac PSU. Personally, I don't mind having 2 cables connected.
 

tj2806

macrumors newbie
May 20, 2024
2
1
Here are my overclocking results if anyone is curious -

Panel: LM270QQ1-SDB1
Board: JRY-W9CUHD-AA1
Power: 24V 6A 144W
GPU: RTX 3080 Ti
Data: DisplayPort 2.1 Cable

Stonetaskin advertised refresh rates:
5K@60Hz
4K@120Hz
1440p@144Hz


Actual Refresh Rates:
5K@61Hz (62Hz = black screen)
4K@100Hz (120Hz = severe artifacting)
1440p@240Hz (280Hz= severe artifacting)

One other misc thing - on the JRY board OSD, there is an option called "Response Time" with options of 'Low', 'Medium', 'High' or 'Off'. Default is 'Off', and when set to 'High', there is a visible line down the center of the screen during high-motion videos and things of the like. It looks like this option refreshes each half of the screen as fast as possible and disregards trying to sync the two together. Very interesting.

Overall I'm quite impressed with the 1440p results & it provided an enjoyable gaming experience in Counter-Strike. For more casual gaming, I'll likely choose 4K@100Hz. I was really hoping to hit 69~70Hz @ 5K though, oh well...
 
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Aiwi

macrumors member
Oct 21, 2010
80
71
Here are my overclocking results if anyone is curious -

Panel: LM270QQ1-SDB1
Board: JRY-W9CUHD-AA1
Power: 24V 6A 144W
GPU: RTX 3080 Ti
Data: DisplayPort 2.1 Cable

Stonetaskin advertised refresh rates:
5K@60Hz
4K@120Hz
1440p@144Hz


Actual Refresh Rates:
5K@61Hz (62Hz = black screen)
4K@100Hz (120Hz = severe artifacting)
1440p@240Hz (280Hz= severe artifacting)

One other misc thing - on the JRY board OSD, there is an option called "Response Time" with options of 'Low', 'Medium', 'High' or 'Off'. Default is 'Off', and when set to 'High', there is a visible line down the center of the screen during high-motion videos and things of the like. It looks like this option refreshes each half of the screen as fast as possible and disregards trying to sync the two together. Very interesting.

Overall I'm quite impressed with the 1440p results & it provided an enjoyable gaming experience in Counter-Strike. For more casual gaming, I'll likely choose 4K@100Hz. I was really hoping to hit 69~70Hz @ 5K though, oh well...
Wait, you’re telling us you are able to drive a 5K iMac panel (LM270QQ1-SDB1) at 1440p 240Hz?!

Can you provide some more info on this?
 

soundog

macrumors newbie
May 29, 2024
8
10
I'm in the middle of converting my 27" late 2015 iMac for monitor use with an M1 Mini. Having upgraded the iMac several times over the years, I swore I'd never again use that evil sticky tape to bond the screen to the frame. So ... I threaded 60# fish line through the top of the silver backlight cover, and tied the ends to form a tight loop. I then attached one end of a small bungee cord to the loop, threaded it through the Apple logo (already opened for ventilation) and attached the other end to the stand.

The bottom of the display rests comfortably in the lower bib (gravity is your friend), and the bungee puts just enough "pull" on the top of the display to hold the whole thing firmly in place. If I need to open the iMac, I can easily tip the display forward by releasing the lower bungee connection and adjusting its length. I may consider a flexible tape across the bottom to act as a safety hinge, but haven't felt this was needed.
 

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fhall1

macrumors 68040
Dec 18, 2007
3,848
1,277
(Central) NY State of mind
I'm in the middle of converting my 27" late 2015 iMac for monitor use with an M1 Mini. Having upgraded the iMac several times over the years, I swore I'd never again use that evil sticky tape to bond the screen to the frame. So ... I threaded 60# fish line through the top of the silver backlight cover, and tied the ends to form a tight loop. I then attached one end of a small bungee cord to the loop, threaded it through the Apple logo (already opened for ventilation) and attached the other end to the stand.

The bottom of the display rests comfortably in the lower bib (gravity is your friend), and the bungee puts just enough "pull" on the top of the display to hold the whole thing firmly in place. If I need to open the iMac, I can easily tip the display forward by releasing the lower bungee connection and adjusting its length. I may consider a flexible tape across the bottom to act as a safety hinge, but haven't felt this was needed.
Definitely unconventional, but you don't see the back anyway, so who cares what's going on back there!
 

soundog

macrumors newbie
May 29, 2024
8
10
Definitely unconventional, but you don't see the back anyway, so who cares what's going on back there!
For sure. There are likely better-looking ways to do a similar thing rather than using a bungee cord and Apple logo cutout, but I am focused on function over aesthetics. I challenge others to find an elegant way to avoid having to glue their panel down with that gawd-awful sticky tape. BTW, this thread has been invaluable for figuring out how to do a 5k monitor conversion....so thanks to all who have contributed here!
 

Edge

macrumors regular
Jul 28, 2005
132
26
However, personally, I wouldn't trust my laptop power management to the JRY and an old iMac PSU. Personally, I don't mind having 2 cables connected.

Many of us here share your apprehension about relying on the JRY board for USB PD management.

I have been wondering how to use my Apple 140W charger to make this project more reliable and more convenient. Apple make some of the finest power adapters and chargers.

Teardown of Brand New Apple 140W USB-C GaN Charger

I have just received one of these USB-C to DP cables which allows you to plug in your own USB PD charger and "reverse" charge the laptop by "adding" up to 94W (20V@4.7A) to the DP end of the cable itself and sending it "back" to the laptop in the opposite direction to the DP Alt-mode signal to the monitor.

Using a third-party 100W charging cable with the Apple 140W charger usually retains the Apple charger information as follows;

Code:
AC Charger Information:

  Connected:    Yes
  ID:    0x7019
  Wattage (W):    94
  Family:    0xe000400a
  Serial Number:    C4H15***********F
  Name:    140W USB-C Power Adapter
  Manufacturer:    Apple Inc.
  Hardware Version:    1.0
  Firmware Version:    1040073
  Charging:    Yes

But when using the same 100W charging cable combined with the USB-C to DP cable, it strips out the Apple charger information, but successfuly negotiates a 94W charging rate.

The final result with this cable would be 2 power cables to the JRY board inside the 5K enclosure, and a single USB-C cable running to the Macbook with both DP Alt-mode and 94W charging which is supplied by the Apple 140W charger.
 
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stefan786

macrumors newbie
Apr 17, 2024
7
10
Quote: @stefan786 "Now the next step would be using the original power button instead of the one on the small JRY controller board."

If you connect the iMac’s original power button wires to the JRY Control Strip power button connections then the iMac button will switch on/off the JRY board.
These links from earlier in this thread discuss doing that.
Here's a pic of the R1811/R9A18 Control Strip modification.

Or you can connect the iMac's power switch wires to the correct wires in the flat cable between the JRY and the controller strip.

View attachment 2376973

If you want the iMac power switch to also control the iMac PSU - with the iMac power button plugged into the PSU as normal, then you are going to provide a more complicated circuit, using an isolation relay (powered by the PSU output's 12v) to make an isolated switch make a momentary connection to turn on the JRY board.

This is more complicated than it sounds...
Thanks so much @PaulD-UK – as you suggested, I connected the iMac's power switch wires to the correct wires in the flat cable between the JRY and the controller strip, and it works splendidly <3 It's worth noting that the polarity doesn't matter (as someone wrote earlier in this thread).
 
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soundog

macrumors newbie
May 29, 2024
8
10
I just finished my 5k monitor conversion using a JRY-W9CUHD-AA1 board ($112 AliExpress, and it arrived in 10 days). I'm using this monitor with a Mac Mini in a home recording studio. Here's what I ended up doing:

- I used the iMac's 12V power supply with the stock AC cord. I won't be powering or charging any peripherals off of the JRY board, so feel that the supplied voltage will be adequate. I'll be monitoring the interior temperature to make sure I don't more ventilation or a fan.

- I wired the iMac power button to the JRY control strip as detailed earlier in this thread, which worked as expected. If I want to turn off the PSU completely, I have it plugged into a switchable power strip.

- I used a single USB-C (Mac end) to DP1.4 (JRY end) cable for connectivity. I routed it through the Ethernet hole in the back of the iMac. I have peripheral hubs for my Mini, so won't be using any other ins/outs in the monitor.

- I didn't change any of the JRY control strip OSD settings, as everything looked good out-of-the-box. I did change Chinese to English, and am attaching a screen shot of the JRY menu in case others need to figure out how to navigate to the setting. I left the control strip inside the monitor, but if I need it I can reach it through the RAM door.

- My studio is already equipped with plenty of speakers, so I removed the iMac speakers (a 1-1/2" woofer? Seriously?!!). I don't want to listen to tiny speakers housed in plastic, and then sealed inside an aluminum case. Likewise, I don't need a camera or microphone in the monitor, so I didn't have to worry about that either.

- The JRY board cost significantly less than the other 5K boards. I don't care "a bit" about 8- versus 10-bit; I'm not doing color-critical graphic work. The output from this board looks as beautiful to my eyes as the original iMac did. Yes, this is a newer board ... but the layout and design looks first-class, and it was manufactured by StoneTaskin who I believe also make the R1811, R9A18 and U49 driver boards. I'll report back if it explodes!

- Cost? I already had the old 2015 iMac, so only spent an additional $112 for the board and $16 for the DP cable.

- I'm still working on an elegant solution for holding the display glass in place while allowing for quick and easy opening of the monitor. I'm no longer using the temporary bungee, and am focused on a small adjustable strap that attaches to the back of the display and threads through a small slot in the rear of the monitor. I refuse to use any more of that two-sided devil's tape!

Thanks again to everyone who has shared great ideas and insight in this thread!!
 

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soundog

macrumors newbie
May 29, 2024
8
10
I have the setup described above. The internal, ambient temperature inside the monitor case has leveled off at 84.9ºF (29.4ºC). Does that seem like a reasonable temperature, or should I consider adding a small fan?
 

stefan786

macrumors newbie
Apr 17, 2024
7
10
It's the components' temperature you'd need to measure. However, in computer terms, this seems a very low temperature. I'd become concerned if the GPU temperature gets above 160°F (70°C), and that would probably result in higher ambient temp than you have measured. I don't think it's necessary to add a fan, but if you do, add the biggest one you can (the smaller they are, the more noise they make).
 
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PaulD-UK

macrumors 6502a
Oct 23, 2009
576
268
My monitor, which does have a low speed quiet fan (inaudible), and is sealed, has an external case temperature of 27.6ºC where the internal PSU is mounted held against the back aluminium.
The screen glass directly in front of the R1811 heatsink/fan is 28º C.
Everywhere else is a degree or two cooler.

The monitor has been running like this for several hours most days for the past 14 months, without any problems whatsoever.

The main source of heat seems to be the RTD2718Q video board controller chip, which is used with all the current boards, so as long as the heatsink cooling the RTD2718Q doesn't exceed about 65º C (150ºF) then there shouldn't be anything to worry about.

Cooler would be better, of course. Especially with the JRY's tiny heatsink.
 

soundog

macrumors newbie
May 29, 2024
8
10
Interesting, thank you! I am a little concerned about the small heatsing on the JRY, but am assuming the EE knew what he was doing when he designed it.

I was considering a small fan that would power off the JRC USB-A port. I would mount it so it would move circulate cool air in, hot out. Here is the fan I was looking at.

Good idea?
 

PaulD-UK

macrumors 6502a
Oct 23, 2009
576
268
Looks good, nice low speed and relatively quiet at 17dBA , and less at reduced speed.
If you can arrange for the warm air to be vented outside the case that will keep the interior cooler.
But blowing air across the heatsink will be best to keep the board's temps down.

I originally bought a fan that size, but found it too thick, so ended up using the fan from a 2012+ 21" iMac
 

soundog

macrumors newbie
May 29, 2024
8
10
Useful info, thank you again! I think I'll go with that size fan (80 mm) and channel the airflow so it moves over the video board. FYI, it turned out I needed both Thunderbolt/USB-3 ports on my Mac Mini for other things, so I decided to try the Mac HDMI output into the JRY (instead of USB3->DP). This worked surprisingly well, and I'm happy with the resolution choices and image quality. It's good enough for my needs.
 
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PaulD-UK

macrumors 6502a
Oct 23, 2009
576
268
You're getting 4K through the HDMI input?
I've tried HDMI/4K with my monitor, and I agree the scaling to match 5K's 2560x1440 is very good - because the screen quality is so good!!
 

soundog

macrumors newbie
May 29, 2024
8
10
3840x2160, 2560x1440, 2048x1152, 1920x1080 (default), 1600x900, 1280x720

Yes, 4K through HDMI. Nice. I'm settling in on 2048x1152 which works good for my less-than-ideal eyesight!
 

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