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glennoconnell

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Mar 5, 2016
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So I have my 5k iMac and separate Windows PC side by side.
The PC display has died.
Is there any way to use the iMac as a monitor for my PC temporarily?
Doesn't have to be at 5k resolution or anything.
Looking at the back of the iMac it doesn't look possible, but maybe you guys know a way?
Thanks for any help
 
Unfortunately, the iMac 5K does not support external video input so it cannot be used as a display for another computer (PC or Mac).
 
No I don't think it's possible as it is disabled on the 5K iMacs. One reason is that it's not possible to transfer a 5K image over a single port on the iMac.
 
No I don't think it's possible as it is disabled on the 5K iMacs. One reason is that it's not possible to transfer a 5K image over a single port on the iMac.

As I understand it, the reason is due to the custom timing controller the iMac 5K uses to display a 5K image cannot work with an external video signal.
 
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So I have my 5k iMac and separate Windows PC side by side.
The PC display has died.
Is there any way to use the iMac as a monitor for my PC temporarily?
Doesn't have to be at 5k resolution or anything.
Looking at the back of the iMac it doesn't look possible, but maybe you guys know a way?
Thanks for any help
You can use Microsofts remote display app that supports RDP.
 
As I understand it, the reason is due to the custom timing controller the iMac 5K uses to display a 5K image cannot work with an external video signal.

The reason is that it is Apple. Being able to use the iMac as a monitor might allow you to reuse the display instead of purchasing a new iMac. It might even allow someone to switch to PC. Previous macs did allow this but it was far from workable.
 
Yes I know about Target Display Mode but this isn't really a workable solution. I want to take the iMac apart, remove the motherboard, hdd etc and solder up a HDMI cable somehow. Is this possible? I would also like to solder a USB cable to the webcam, which I think should be easy enough if it is indeed USB internally. Soldering an audio cable to the speakers would be easy. I could even solder a USB hub to the internal USB ports and possibly even get the CD drive working. The hard part is the screen. Does anyone know what interface the screen uses internally? I think the end result would be pretty cool if it worked. A regular PC tower that is actually upgrade-able and can be worked on without having to deal with the absolutely horrible design of the iMac internally (trust me they only look like a nice design on the outside, internally they are a disaster of poor design).
 
The reason is that it is Apple. Being able to use the iMac as a monitor might allow you to reuse the display instead of purchasing a new iMac. It might even allow someone to switch to PC. Previous macs did allow this but it was far from workable.

Conspirations over. I don't think that's the reason. There are very good technical reasons for that limitation.

Previous solution (target display mode) was very workable. Not sure what you mean.
 
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Well, I am surprised that you can judge the "poor design" thats inside the iMac and yet can't figure out where to solder the HDMI cable and how to decode the custom timing bus used by the paradise DP665 controller :)

Sorry, but what you want is a total nonsense...
 
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What you are talking about maybe virtually impossible due to limitations imposed by the firmware. Unless you mean soldering directly to the screen without any hardware layer lol. Get a 4k monitor with everything you need built in (speakers, usb hub,.....a functional screen....).

There is nothing wrong with the internal design of the iMac, in fact its quite impressive when compared to other all-in-one computers. I grant you its not the easiest to work on but it wasnt designed to be so that isn't design at all....
 
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The reason is that it is Apple. Being able to use the iMac as a monitor might allow you to reuse the display instead of purchasing a new iMac. It might even allow someone to switch to PC. Previous macs did allow this but it was far from workable.

Nope. It's a technical issue.

You could use a 27" iMac as a display for an external PC through the 2010 model, which was the last that used a direct DisplayPort connection. With the 2011 model, Displayport has been carried over Thunderbolt and you could only use Target Display Mode with another Thunderbolt Mac.

And as I noted above, with the 5K models, Apple had to develop their own custom timing controller because DisplayPort 1.2 can't drive a 5K display at 60Hz. This controller does not adhere to the DisplayPort 1.2 spec, so it cannot take an external DP 1.2 signal (like from a PC or other Mac), which is why the 5K iMac does not support Target Display Mode.
 
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Interesting replies. I'm not sure why what I want is total nonsense. That reply itself is total nonsense I guess. As for me not being able to do it, well I don't have every piece of information I require but I have the ability to gather information and complete a task like this. That is why I am asking. AppleNewton, yours is the only sensible reply, it could be a waste of time however it is still a full HD screen with a webcam and speakers built in. :) Cynics, there is absolutely no question it is a terrible design. One of the worst products I have ever had to work on. Things that are a good design internally are easy to work on. The iMac is comically bad, designed so that it's very easy to damage parts. They actually have the SATA cable, a cable that is designed to be serviceable, durable and removable many times in behind the screen. That means you need to remove delicate, easy to break ribbon cables that are only designed to be removed a few times at best in order to get to the parts that are meant to be serviceable. That IS a bad design and just the start of it. You admit it yourself when you said it is actually designed not to be easy to work on.

Anyway, I think I got it sorted, you can purchase HDMI to LVDS converters for around $30. Soldering speakers should be easy, USB too.
 
I saw your post here https://forums.macrumors.com/posts/23157636/

I don't consider myself technical but even I know the 5k iMac uses a custom TCON chip because DP 1.2 doesn't support the bandwidth required for 5k pixels. That's why target display mode isn't available on that model, not as you say 'the reason is that it is Apple'. They made a big deal about it when they launched and the information is readily available.

You didn't realise that so it suggests you're not half as clever as you think you are. But by all means please post a video of your your project when all the parts you speak of are working.
 
Complete waste of time. You can sell the iMac, and then use that money to buy a really nice 27" IPS screen and a webcam.
 
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Glad you got it sorted. A few post above you asked where to solder HDMI and what kind of interface does it use internally, so you are progressing fast... Which HDMI-LVDS exactly converter are you getting and what is your plan with power source once you remove all the electronics :)

Now I understand what you mean by "poor design". No, the iMac is not designed to make it easy for you "to work on it" or to be a good base for DYI projects. No internal part is designed to be easy serviceable and removable many times. Also there is nothing wrong about flat ribbon cables. I would be actually interested to know what cables are you using in your superior designs :)
 
Or go on eBay to look for a lcd converter to display port which should likely work. I do agree with the internal design of iMacs from 2009-2011 were a horrible design and heated very badly on the external case but 2012-2015+ had a great clean internal design with very little use of cables and the external case does not heat up terribly during idle or under load unlike the older design mostly on the top area of the housing could burn your hands which I think is a one of the examples of a poor design due to likely the very thin back vent slot which didn't force all of the hot air out thankfully newer models don't have.
 
Anyway, I think I got it sorted, you can purchase HDMI to LVDS converters for around $30. Soldering speakers should be easy, USB too.

How are you going to power it? Seems like you need the MB to turn the PSU on / off.

Even if it works, it is a very huge, heavy display with no flexibility of ports or adjustments.
 
I saw your post here https://forums.macrumors.com/posts/23157636/

I don't consider myself technical but even I know the 5k iMac uses a custom TCON chip because DP 1.2 doesn't support the bandwidth required for 5k pixels. That's why target display mode isn't available on that model, not as you say 'the reason is that it is Apple'. They made a big deal about it when they launched and the information is readily available.

You didn't realise that so it suggests you're not half as clever as you think you are. But by all means please post a video of your your project when all the parts you speak of are working.

I don't know everything about everything. I know enough to be confident in my knowledge. I had forgot what the apple community was like. You can bag the crap out of Microsoft on a MS forum and no one gives a stuff. In Apple forums everyone gets all offended. My point in that other thread was if apple wanted to make it possible they would have. They could have invented another connector or simply run it at a lower resolution for external inputs. These crazy resolutions are about as useful as clippy was in office 2000. Allowing an iMac to really functional properly as a screen might stop people throwing them out after their underpowered hardware becomes too slow and that would benefit their customers.
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Glad you got it sorted. A few post above you asked where to solder HDMI and what kind of interface does it use internally, so you are progressing fast... Which HDMI-LVDS exactly converter are you getting and what is your plan with power source once you remove all the electronics :)

Now I understand what you mean by "poor design". No, the iMac is not designed to make it easy for you "to work on it" or to be a good base for DYI projects. No internal part is designed to be easy serviceable and removable many times. Also there is nothing wrong about flat ribbon cables. I would be actually interested to know what cables are you using in your superior designs :)

I was looking at this one http://www.chalk-elec.com/?page_id=1280#!/HDMI-to-LVDS-converter/p/14647633/category=3094861

I agree there is nothing wrong with ribbon cables. They are designed for stuff like LCDs where you are unlikely to remove the cables very often, if ever. However there is no question they are less durable that something like a sata plug. In my experience flat ribbon cables often fail. Sata connectors on the other hand are much more durable, designed to be removed 100s or even 1000s of times. My dislike with the iMac design is not that they use ribbon cables, but that they make it so you need to remove many ribbon cables to get to the HDD. It is simply poor design to have a durable connector, designed to be user serviceable, behind many ribbon cables. In all my laptops the HDD can be removed easily. It is a terrible design where you need to remove the screen to change a HDD.
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Thanks btrach. Unfortunately that is $2000, a little more than I want to spend :). My current PC I have had the case for at least 10 years and the monitor almost 8. It's still higher than full HD res with webcam and cost about $300. My PC I upgraded a few years ago for $500 to an i5. So budget over the last 8 years might be $1000.
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How are you going to power it? Seems like you need the MB to turn the PSU on / off.

Even if it works, it is a very huge, heavy display with no flexibility of ports or adjustments.

I can either power it from the power supply in the mac or by running some power from the PC. With ATX power supplies in the PC you can turn them on by bridging one wire. I presume the same thing would be possible in an iMac. As for being huge and heavy it's not really that big a deal. With regards ports it only needs one. I'm pretty sure I could wire up the USB ports so they worked.
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Complete waste of time. You can sell the iMac, and then use that money to buy a really nice 27" IPS screen and a webcam.

The iMac is not working so sale price won't be fantastic. I agree it would potentially be a waste of time but lots of projects are, right? :) My wife really likes the simplicity of the iMac and it does look pretty good, even to an apple hater such as myself :)
 
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Nope. It's a technical issue.

You could use a 27" iMac as a display for an external PC through the 2010 model, which was the last that used a direct DisplayPort connection. With the 2011 model, Displayport has been carried over Thunderbolt and you could only use Target Display Mode with another Thunderbolt Mac.

And as I noted above, with the 5K models, Apple had to develop their own custom timing controller because DisplayPort 1.2 can't drive a 5K display at 60Hz. This controller does not adhere to the DisplayPort 1.2 spec, so it cannot take an external DP 1.2 signal (like from a PC or other Mac), which is why the 5K iMac does not support Target Display Mode.

Dell got around that by running 2 display ports. This is something that Apple could have done if they wanted to. They could have also run it at a lower resolution for external connections. They could have invented a faster connector. Basically they could have done it but dropped it claiming technical issue because it had the potential to stop people throwing away their hardware when it gets too slow and that does not benefit apple.
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Conspirations over. I don't think that's the reason. There are very good technical reasons for that limitation.

Previous solution (target display mode) was very workable. Not sure what you mean.

In order to use the iMac as a screen you needed to have OSX installed and have the iMac running and have a keyboard attached. If you want to upgrade to a PC and use the iMac screen (something I have been able to do with all my PCs) then it is not very workable. You are basically powering 2 computers.
 
I don't know everything about everything. I know enough to be confident in my knowledge.

You didn't know that the 5K used a custom TCON. This is not a big secret. It's relevant because this is the sort of stuff you want to mess about with. Your confidence in your knowledge is misplaced.

They could have invented another connector or simply run it at a lower resolution for external inputs.

That would just give you something else to whinge about, 'Apple using non-standard connectors'.

These crazy resolutions are about as useful as clippy was in office 2000.

If you can't see the difference between a Retina screen vs standard then you need your eyes tested. Are they critical? No. But neither are faster processors, GPUs, RAM or storage. Do you want to whinge about those too?

Your complaints about the design of the iMac is very much like moaning a Ferrari can't be taken off road. Your demands are not it's design goals. Do yourself a favour and just buy a new monitor.

But if you insist on continuing this path, please post a video link when you get all the stuff you say you can working.
 
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