Thunderbolt Display USB-C Retrofit for Modern Macs!

'Behind the screen' details of how I modernized a Thunderbolt Display to keep using it with a new M1 MacBook Pro.

Completely hidden, no desktop dongles, still just two connections, but now they are both USB-C.

The Thunderbolt Display still charges my MacBook, and the MacBook now runs 3 external displays and more with just 1 cable!

Please be aware: The procedure in this video involves opening and modifying an AC mains powered device. The left side power supply board has many exposed solder joints, and capacitors may store charge even after power is disconnected. You should not need to handle this board or plug in the open monitor, but proceed with caution anyway, and if in doubt, check with a meter.

Be aware, be safe, but don't be afraid!

Here's one of the meters I use, to test USB based power:

Here's the full parts list:

USB-C Power Delivery Buck Converter:

USB-C Power Delivery cable:

Apple Thunderbolt 2 to 3 adapter:

Apple Thunderbolt 2 short cable:

Thunderbolt 3/4 extension cable:

Schottky Barrier Diode
(this is what I had on hand, but any Schottky Diode rated above 5A and 25V should work the same way)

39.4KΩ resistor (or as close as you can find to it), rated 1/4 Watt or higher
Either buy a resistor kit that includes 39K resistors, like this one:
Or else you'll probably have to buy a whole bag of them! But they are inexpensive:

1/2" or 5/8" Grommet:

[tenorcello]

Thank you for the video - as I have few Thunderbolt displays in hands. I have tried to use the MagSafe for older MacBook Pro and MacBook Air. I have grown to DISLIKE the power cable portion - it created the tension on the most precious Thunderbolt 2 connector, which I saw on many Thunderbolt Display. I have disconnected the Octopus cable's internal power connector, then cut off the external power cable. However, aesthetically, it looked ugly with the TB2-> TB3 adapter, plus the thickness of the the remaining cable. I really like your method of hiding the adapter internally and only has TB3 cable coming out. During my modification, I cut the 0.5m TB2 cable's plastic cover and it shows the "connector" exactly the length and style like the OEM's Octopus internal TB2 connector! So, I can use the connector's cover, without needing the glue! I also save Octopus cable's the white center "button" for the TB3 cable to pass through (again, with cutting and gluing) - now it feels like the TB3 cable was part of the TB Display... It suits perfectly for my M1/M2 Mac Minis. Thanks again for inspiring me to make this modification!

[wm-d-repairman]

Thank you I was able to follow up on this instruction and finished the mod. I used the original grommet and let the thunderbolt 3 to 4 adaptor's usb-c connector out of the monitor just in case I have to replace the extension cable.

[deeteegee]

I just completed this same change minus the power because my thunderbolt cable finally died from the bends. This video was very helpful, thank you! Although I has issues when connecting this to a new Mac mini. I ended up having to skip the thunderbolt extension cable you called out here. Apple thunderbolt cable to apple convertor was the only way it would work for me.

[ivankind]

That’s awesome!!! Thank you so much for sharing your experience🙏🙏🙏

[Liftd]

This is wild! I wish I could get my old thunderbolt working again .. not sure if the wires or the psu are bad

[stevenlord]

Excellent video - thanks! I too have an "intermittent" display cable and need to replace it and so will use your method. Here are two rather naïve questions. First, since I never use the MagSafe power cord anyway (I easily charge my MacBook Pro with its own charger) I'll just skip that part entirely, and replace the video cable only. So question 1 is - is there anything wrong with that plan? Question 2 is why did you need to do all the voltage conversion in the first place? Are the voltage needs of the new MacBook so different? Why isn't it just a connector change, like for the video? Lastly, I am not sure how to take the existing Magsafe power cord out of the picture - just unplug within the display, or tie it unused on the outside, unused, to the new 3/4 extension cable. OK - now to go out and buy some suction cop and T6 and T10 torx heads. What was the T number for the display frame, BTW? Thanks!

[jamesotoole]

@colindgrant Thank you for posting the video! Aside from price could you theoretically take the power line, add a USB-C extension (female end sticking out of the shell) from the Delivery Buck, and then just add a MagSafe3 from it? Also, if you have a moment would you mind posting a video of how you connected the USB-C Power Delivery Buck Converter together with resistor, and diode?

[alexandregillan]

if I just want to use it for video via thunderbolt, can I do like you did with the adaptor inside and use a thunderbolt 3 extension cable to my mac? leaving the magsafe unplugged inside? you did incredibly well everything, congrats on all the work.

[carlosvaras]

Bro with all the M class macbooks out and people trying to get rid of their thunderbolt displays why not make a kit fopr people to replace. I sure would buy it!!

[gefthetalkingmongoose]

Alternatively just attach Thunderbolt-to-USB-C and MagSafe-to-USB-C adapters to the end of the breakout cable. That's what I did, works fine.

[HaHaDK]

Any reason why you replaced the thunderbolt 2 cable inside the monitor, and not just use the one it had by by plugging the adapter directly to it? Any advantages to that? Amazing video btw, it is very inspiring!

[josephpadilla]

Can you do the conversion without doing the power conversion, more interested in change the video output to usb c as i dont mind charging my 2016 MBK pro with its original charger

[DavidMalcolm]

I use 2 TB monitors with my Mac. You also could get around the busted cable by connecting the Mac to the thunderbolt port on the monitor with another cable.

[AdiAgafitei]

Would it be possible to join the data cable and the power cable into a single output from the monitor?

[qshocksp]

Which is the best option for simple tasks such as text editing: Thunderbolt Display or a cheap 4k display?

[VOLTRONDEFENDER]

if the type c supplied power then you dont need magsafe 3 connector if using one cable only

[jeremylovechild]

willing to sell an PD module already put together? i want to do the same upgrade but using a usbc to magsafe cable for my m2 macbook pro

[certeez]

Great tutorial Colin! you could use this LINDY L43246 mini display port to usb-c with power delivery (it's also very cheap) and have only 1 usb-c cable my only problem now it's how to implement in this setup a usb for my mouse because i'm using logitech g pro mouse.

[LauraEvansPiano]

So if you only want to do the display portion and not have any power go to your Mac, you do not have to mess with the power supply, right? The only part that one would do is the first.

[sambowks]

Could you have spliced the power and display signal together into one usbc?