Turn 27' iMac 2013 into monitor

[kriss13]

Hi

It is my turn to convert my 27' iMac 2013 into a stand alone monitor.
Not many information about his model, I see posts for either earlier 20009-20011 ones and 5k ones.

The plan is to put a hub inside and use all the port holes behind it except one of the TB ones which will become USB-C to conect to my laptop for image, sound, LAN, web cam etc.
Also I want tu use the internal speakers, replace the web cam with a usb one + mic.
I will use mini HDMI ports to fit the holes, and other alternative connectors since this is my display , I can deal with these



It also crossed my mind to use the internal space for an EGPU, but this is another story.

Now, I have to purchase the driver board, but not sure which one.
I see there is a bigger 2nd board for the one with DP port not sure why.




Any of you have an idea what are the main deferences?

 

[PaulD-UK]

@kriss13
The two pictures of boards are the same board, but the left one has an external backlight constant-current board, and the one on the right is using backlight circuitry that is built into the board - and which both boards have.

The problem with driving the 2010-2011 iMac's screen panel with these driver boards are that the backlight is too dim, as they don't match the 2010-2011screen voltage.

I have heard of people having the same problem with post-2012 2K iMac screen conversions...
But I have also heard of people who are happy with the conversion.

Most probably the extra backlight driver board is an attempt to solve this problem.
But this same extra board doesn't work well with 2010-11 screen panels, because the voltage is OK, but the PWM frequency is wrong.

The board with a blue VGA socket is an older board, and is mostly sold for 21" 1080p iMac conversions.
On AliExpress vendors advise that for @K conversions, the VGA board's "brightness of this board is not as bright as the original control board."
Unfortunately the board in your first picture is using the same backlight board..

I'm sorry I don't have any direct experience of 2012-13 iMac conversions, but the board you have linked to seems to be the best choice. It look like it's got a RealTek video scaler chip in it, and the 5K equivalents from RealTek work very well for 5K conversions.

If you found that the backlight of your conversion isn't bright enough, there is a higher rated Constant Current board for use with 5K iMac panels which looks like it has the same circuitry as the 2k version, so might be usable...
Further investigation would be needed to confirm this. I've built a 5K conversion so have had some experience...

There is information about using the iMac's existing ports etc scattered through the second half of the DIY 5K forum.
This one has details of an Ethernet conversion, also he's using the additional backlight driver board. And the rest...

 

[kriss13]

Thank you for such a detailed answer. I will try my luck with the board that has the extra board .

"...there is a higher rated Constant Current board for use with 5K iMac panels which looks like it has the same circuitry as the 2k version...", Do you have an example. Are referring to a second board from a 5k kit that is compatible with the one above?

 

[PaulD-UK]

@kriss13 "Are referring to a second board from a 5k kit that is compatible with the one above?"

There is a board, the DZ-LP0818 (the blue PCB in the pictures in the link in my original post), which has the same 6 wire interface, but whether it's electrically compatible hasn't been determined.
Someone with electronic diagnostic skills, and equipment, would have to test it's compatibility and performance