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The first post of this thread is a WikiPost and can be edited by anyone with the appropiate permissions. Your edits will be public.
@razmanugget "Do most of you feel it is worth it to do this conversion?"

I don't think there would be 588K views and 2K+ replies to this topic without it having real value. :)

"I found a deal on a broken video card 2015 5k iMac for €160. I can't confirm the screen is working..."

That is a bit of a risk as you haven't seen if the screen works, and if there are any visible signs of aging, which the 2015 Mac screens are known to suffer from.

However using a 2015 iMac DIY monitor is certainly worthwhile if everything is working as it should, though later screens can give even better results...

"Usually, I enjoy projects like this, but I'm guessing it's 40 hours of work and research in order to save €600."

That's for you to decide. Most probably the saving is even more, and the quality and viewing experience of the iMac screen is SO much better than cheap/mid-price 4K screens...

Most of the research has already been done by the previous 2K contributors here. 😃

My personal view is:
Later 2017 onwards screens are better, and less old, so probably have a longer future life.
Consequently, if you wish to build the best 5K monitor you can, start with a later screen.

So, for an older screen, choose a cheaper video driver card to fit in it.
Like a R9A18, or a JRY-W9RQUHD-FA1.
If you need USB-C PD power for a laptop, then a JRY-W9RQUHD-SA1 has a USB-C input port.

For anyone with a late-2014 screen, then it would be quite reasonable to choose the most basic video board, the JRY-W9CUHD-AA1.

@mmyk "I, however, have very little experience with electrical projects so I see this is like a nice opportunity to learn something new."

👍 That is indeed the basis of undertaking this type of project.
And buying the tools needed if the conversion needs them, if you don't already have them.

Edit:
€160 is a fair price for a 10 year old iMac screen in good condition, without pink edges etc...
If you trust the vendor then there is no real problem.
But a broken 2015 iMac is not exactly a valuable commodity.
Who else will buy it?
Only someone who is prepared to take the risk. ;)
Love this advice. Thank you!

Maybe I'll wait and go for a 2017 screen instead
 
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BTW, the first post is now a WikiPost. Who wants to make the first edit? It should keep the info of the first post, maybe reorganize it if necessary, and summarize new and interesting info from the rest of the thread.
 
@joevt Plans are in hand. It needs to be done meaningfully.
We have been waiting for @fiatlux to respond, but it seems he hasn’t dropped by recently. 😉
 
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My JRY-W9RQUHD-SA1 board arrived today. Has anybody knowledge about the polarity of the power input?
I assume the inner pin is +, but i dont like to try it before i have a confirm about it.
 
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Do most of you feel it is worth it to do this conversion? I found a deal on a broken video card 2015 5k iMac for €160. I can't confirm the screen is working, but I'm a little tempted to try.

Usually, I enjoy projects like this, but I'm guessing it's 40 hours of work and research in order to save €600.

What are your thoughts?
Definitely worth the total of approx. $500 I paid for the late 2015 iMac and assorted parts (after reselling the iMac logic board on ebay). Even on sale you're looking at $1200 for an ASD - which has a fan in it which some people say they can hear. My build is fanless and totally quiet to go along with my fanless M2 MacBook Air.
 
My SA1 board arrived, and I've been very busy designing 3d parts (so far, a board base and the PSU holder, got some ideas for the ports).

Tried the board and is working great, so 'd like to work on the remaining electrical connections, specifically, I'd like to use a small 5d rocker to replace (or use instead of) the small control board with the push buttons (will install it in the network port):

- has anybody tried to use a small 5-way joystick with an SA1 board?
- does anybody have an electrical diagram of the SA1 control board/push buttons?
- for the folks that have already done something similar, did you replace the control board (plugging directly to the main board, or did you solder over the pin connectors in the control board?
- lastly, any picture will be appreciated

I'm planning to use the following Five Direction Navigation Button Module for Arduino

IMG_6221.jpeg
 
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Forgive the intrusion folks but this thread seems to be /only/ place on the entire web where some people have said they've converted a mid-2017 21.5" 4K iMac (the other thread Google returns has 1 reply, with the OP being told to 'look' here for answers).

I recently bought a 14" MacBook Pro and as it's ~10x the speed of my iMac, I want to use it at my desk with a monitor. All of the 32", 27" and 24" 4K monitors I've looked at are… sub-par to the iMac display. They're not as sharp, bright, or glossy as it. If I can repurpose my iMac as a monitor that would be sweet since, y'know, I already have the iMac and a £60 display board conversion is cheaper than plumping for a dim, blurry 4K external.

From what I've gleaned from the occasional older post about it in this thread, the process of converting a 4K is significantly simpler than doing a 5K (oh that I could </3).

Single display board, cables/controls that come off it, and a specific type of 12v DC power adapter. No heatsinks, breakouts, or separate backlight controllers, and speakers work without crossovers (not that I use the internal speakers). Since the 21.5 doesn't have a RAM hatch I'd need to remove the power socket port and thread things out of that (Untidy, but what I can't see won't matter). And I should need use DP not HDMI for best colour/res.

I want to go head and buy the board so I can start enjoying my M4, but the panel model version support bit is confusing me a little, and I don't want to get it wrong.

So, most AE listings for the CY.R9513 boards (which seem to either be V4 or V5 now, if that matters) state they work with LM215UH1-SDA1, SDB1, SPA1 and SPA2 panels, i.e., one board works with all of those. However, a couple of other (cheaper) listings ask me to select which panel I have prior to ordering, suggesting that that matters.

Do I need to open the iMac and check my board? I last opened it in 2021 to upgrade the RAM and tbh the adhesive side was a total chore. As I still use my iMac daily for work, and the display board wouldn't arrive for about 2 weeks at best, I'd ideally like to only have to open it once.

If anyone has knowledge or experience in converting a 21.5" 4K iMac to an external monitor, or any pointers on the process in general from having done it or heard people who have, that would be SUPER appreciated 🙏.
 
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@ItsAShaunParty "What's the deal with these other boards? For example, this one at Aliexpress or this one?"

They are both the same, the JRY-W9CUHD-AA1, which is a lower spec board with a earlier video controller chip.
1. Only 5K/60 8 bit over DP.
2. Only 5K/30 8 bit over HDMI.
3. No DDC keyboard control of brightness or audio level from the Mac (with additional software).
You have to use the button strip.

One further caution is that some of the cheap AA1 boards being sold are 'second hand', having been removed from the m Chinese brand monitors they were originally in.
These ones seem new, and are cheaper because its mostly the more recent better-specced boards that are being ordered in US/EU/UK.
I read your last comment. I have a 2017 iMac. Does that mean I should get the pricey board?

As you can tell, I've been thinking about this a lot.

What am I losing if I buy a simple board for under $100? For example: this.
 
My SA1 board arrived, and I've been very busy designing 3d parts (so far, a board base and the PSU holder, got some ideas for the ports).

Tried the board and is working great, so 'd like to work on the remaining electrical connections, specifically, I'd like to use a small 5d rocker to replace (or use instead of) the small control board with the push buttons (will install it in the network port):

- has anybody tried to use a small 5-way joystick with an SA1 board?
- does anybody have an electrical diagram of the SA1 control board/push buttons?
- for the folks that have already done something similar, did you replace the control board (plugging directly to the main board, or did you solder over the pin connectors in the control board?
- lastly, any picture will be appreciated

I'm planning to use the following Five Direction Navigation Button Module for Arduino

View attachment 2483739
I notice you're keeping the speakers. What's your plan for the LCD board/speakers?
 
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@ItsAShaunParty "I have a 2017 iMac. Does that mean I should get the pricey board?
What am I losing if I buy a simple board for under $100?"


The only <$100 is the JRY-W9CUHD-AA1.
1. It is only capable of 16.7 million 8 bit colour. Other boards do 1.07 billion colours (10 bit).
2. It is only capable of 5K30Hz using the HDMI port. Other boards can do 5K60 using HDMI.

The first is not a problem if you are only going to browse the web, or view YT. The web is mostly compressed to 8 bits. ;)
If you use Photoshop or do picture editing, then 8 bit colour means only 256 steps in a single colour gradient, which is quite noticeable, especially on a 27" screen.

Your 2017 screen has a full colour P3 color space panel, this is Apple introduction to its capabilities in 2017:


So a better 10 bit board can give much better results.

It isn't necessarily a lot more expensive, the JRY-W9RQUHD-FA1 is capable of 10 bit performance, or the slightly more expensive JRY-W9RQUHD-SA1 if you need USB-C.

What the R1811 gives you is better firmware, so you get an OSD which gives more information, and more control.
And it uses an IR remote control.

"What's your plan for the... speakers?"

This thread has gone into audio in some detail in previous posts. 🫨
The R1811/R9A18 have a 10 watt amplifier, and running the speakers through suitable crossover units, can give OK to very good results.
The JRY boards use a 2 or 3 watt amplifier which can give the sort of sound you get in the average $300 monitor.
I don't have personal experience of anything else than my R1811.
 
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Thanks,

I had read @tcapanema's posts but I hadn't come across @sec89's when searching.

Hopefully someone who's bought and used the CY.R9513 can confirm if one board does support all 4 possible panel models used in the 2017 4k (as some listings seem to indicate but as it's machine English from Chinese nuance and specificity can be sus') or if a specific board is needed for a specific model as some other listings seem to suggest.

I don't like the sound of losing 10-bit colour given I edit video, but given most 27" 4k externals are 8-bit anyway, it's by-the-by (and I can colour audit on the MacBook's XDR display).

It's great to *see* it can be done/does work though.
 
Thanks,

I had read @tcapanema's posts but I hadn't come across @sec89's when searching.

Hopefully someone who's bought and used the CY.R9513 can confirm if one board does support all 4 possible panel models used in the 2017 4k (as some listings seem to indicate but as it's machine English from Chinese nuance and specificity can be sus') or if a specific board is needed for a specific model as some other listings seem to suggest.

I don't like the sound of losing 10-bit colour given I edit video, but given most 27" 4k externals are 8-bit anyway, it's by-the-by (and I can colour audit on the MacBook's XDR display).

It's great to *see* it can be done/does work though.
I have the CY.R9513 V5 (try to get this one as it's got the remote and is the latest revision of the board).

I sent the seller the image below before purchasing from Taobao, to which he replied with "OK".

I think they might change the firmware depending on the revision of the panel, for instance mine was the (SD)(B1).
1740014577134.png


By the way, the black levels were completely off. For the most accurate colour with the R9513 V5, this is what I set in the monitor settings:
PictureBrightness64
ColorGammaOff
TemperatureUserR: 115
G: 114
B: 120
PCMNative

Additionally you can save your iMac 4k's colour profile from /Library/ColorSync/Profiles/Displays to a USB or Google Drive, and reuse it after the conversion for the most accurate colour.
 
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Just an update of my conversion. I placed my board JRY-W9RQUHD-SA1 at the place of the HD, i had an ssd only late 2015 imac. Unfortunately i had to remove the ventilator to get the powersupply connected, that makes the imac unusable at the moment. I drilled a hole at the back of the imac to get the power and usb cable into the imac.
At the top i removed a little aluminum to move out the controlerstrip.
The powersupply remained outside the mac and the macmini is connected via usb, works well.
Unfortunately a tiny crack of the screen increased in size that it now crossed the whole screen. But the screen is working and i can not see the crack when i look normal from the front, the crack can be seen when looking from the side.
At the moment the screen is held by tape from the outside to be able to remove the screen more easy. In future i will try to reattach the ventilator of the imac that the imac can be used with an external monitor. I am aware that i have to handle the throtteling of the imac. I gave up the idear to move out the connectors of the screen that i can switch between imac and monitor use just by replug theconnectors without opening the imac. Tha connectors are too fragile for me.
 
Hi,
Has anyone tried to remove the AC socket (the whole thing with EM filter)? I have removed several screws but it is still held in place by something else.
iMac AC socket.jpg
 
@mmyk It's held in place with glue.
If you use a hairdryer for a while on the outside of the case to get it warm then you can lever the socket off with a thin metal prying tool - I used an old narrow wood chisel, carefully!
 
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@ItsAShaunParty "I have a 2017 iMac. Does that mean I should get the pricey board?
What am I losing if I buy a simple board for under $100?"


The only <$100 is the JRY-W9CUHD-AA1.
1. It is only capable of 16.7 million 8 bit colour. Other boards do 1.07 billion colours (10 bit).
2. It is only capable of 5K30Hz using the HDMI port. Other boards can do 5K60 using HDMI.

The first is not a problem if you are only going to browse the web, or view YT. The web is mostly compressed to 8 bits. ;)
If you use Photoshop or do picture editing, then 8 bit colour means only 256 steps in a single colour gradient, which is quite noticeable, especially on a 27" screen.

Your 2017 screen has a full colour P3 color space panel, this is Apple introduction to its capabilities in 2017:


So a better 10 bit board can give much better results.

It isn't necessarily a lot more expensive, the JRY-W9RQUHD-FA1 is capable of 10 bit performance, or the slightly more expensive JRY-W9RQUHD-SA1 if you need USB-C.

What the R1811 gives you is better firmware, so you get an OSD which gives more information, and more control.
And it uses an IR remote control.

"What's your plan for the... speakers?"

This thread has gone into audio in some detail in previous posts. 🫨
The R1811/R9A18 have a 10 watt amplifier, and running the speakers through suitable crossover units, can give OK to very good results.
The JRY boards use a 2 or 3 watt amplifier which can give the sort of sound you get in the average $300 monitor.
I don't have personal experience of anything else than my R1811.
Again, I really appreciate your help. I'm sure others will benefit from your answers, too.

I found this listing on Alibaba. What would it take to get this board to work? It's an R1811, after all... I tried to ask the seller, but the Alibaba messaging isn't working for some reason.
 
@ItsAShaunParty Interesting... 😱
Presumably $80 for a single board.
I don't see how they could sell the boards for $30 in bulk unless they're old stock or customer returns or some other catch?

I notice lower on on the page a link to the R1811 specified for iMac P3 screens (C1-F1) for $280, the normal price...

The problem with the $80 version would be that the firmware on it may not be the correct one for your LM270QQ1 SD(C1) panel.

However StoneTaskin sell the firmware you would need (as a download).
You have to have a Windows PC with a DP port to connect via DP to flash the new firmware onto the board.

If the cables don't come with the $80 board, StoneTaskin sell the video cable from the R1811 to the screen as a separate item, also the cable and Control Strip board. They don't sell the backlight cable, but they might if you ask for one with all the other stuff...

You could make your own backlight cable as it needs ordinary two JST PH 4 pin plugs, and a JST SH 12 pin plug and socket pair to join to the screen's backlight cable.

All in you would have to pay about the same price as the board for all the extras, and that would save about $80-100 on the price of the full kit and board from a retailer...

EDIT: Your link, which priced an R1811 yesterday as $30-80 is today coming up at $358-360. 😵‍💫
Dynamic pricing...
So posting on a public web page and generating interest isn't something you can do on a Chinese vendor's site.
 
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Hey all, what is the general consensus for JRY SA1/FA1/AA1 board builds regarding cooling? Most of the folks seem to remove original iMac fan. Is the airflow by convection enough for these boards, especially with a PSU mounted inside? Chip radiator gets rather warm in several minutes while outside of iMac case. I don't get burned while touching but I would not be able to hold my hand against it for more than 10s or so. This means that it could be around 50C.
 
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Thanks to the posts in this thread I successfully started the display on the JRY-W9RQUHD-SA1 board. Temporarily connected to a 14V power supply, everything works fine, although I read that 24V is mandatory for this board.

I have a few questions, the answers to which I have not found.

1. On USB-C by default is included colour mode 10bit, but at 10 bits the image is a bit foggy. I switch to 8bit - the image is more contrasty and clear. Is there any way to activate the default 8bit mode in mac os via terminal?

2. Volume control from the keyboard via MonitorControl does not work. The backlight adjustment works via Better Display. Volume control behaves in the following way: when the volume is raised even by one division - the sound disappears, when the volume is turned off (silent mode) the sound appears. It is not adjustable. When switching off the sound is heard a slight crackle in the speakers.


Maybe someone knows what can be done with this, what settings to activate?

3. Sound quality leaves much to be desired. If I put an audio amplifier like XH-A232, will it improve the situation?
 
@alexey-xxx
The JRY boards seem to work fine on 12V, the only thing that requires 24V is USB-C PD to power a laptop.

Strange behaviour of the Colour Mode. Does the 10 bit problem occur if you deactivate Better Display?
The other possible check to try to resolve this is to use a USB-C to DP 1.4 8K cable so you are using the DP input.
That usually gives the best performance with all these boards.
You could also try to power the board at 24V, to see if that improves 10 bit colour.

Monitor Control and Better Display are both controlling the display's audio volume in the same way at the same time.
I'm just using BD and it does both brightness and volume, very effectively.
But the volume setting on the Control Strip is also involved, so I keep that at the same setting so as to not have any effect.
Does disabling MC improve the audio, and give you volume control?

The amplifier chip used by JRY for the FA1 and SA1 boards probably has a high (up to ~10% THD) distortion at the levels needed in a monitor...

I tried a cheap amplifier board, but found the R1811 has (much) better sound.
I'm dubious of Chinese amplifier boards that are being sold at a price cheaper than Texas Instruments sell the audio amp chip that the amplifiers say they use....
The XH-A232 might work, I have no direct experience.
 
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