Messages

You removed the battery and inserted the battery again after inserting the card?

Sorry, what do you mean by "low level format"?
And "doesn't work"?
- Won't let you low level format?
- "Low level format" successful but cam won't start after?

Did you format the card with NTFS or not?

http://wiki.magiclantern.fm/userguide#movie_restart

Windows won't try to boot/autostart programs from the card. The cam will try to load autoexec.bin. And if you messed up with card's content: Cam will get stuck when a bootable card without ML files is inserted.
That's why you were asked to format the card using your cardreader.

Again: Any Canon dealer or repair centre should be able to tell you the price of this spare part. Just the main PCB. Then you may decide if you go with it and replace it by yourself or go for a new or used camera as a replacement.

Any? Yes, if you will find a soldering wizard willing and able to fix this while keeping costs below PCB replacement by a Canon repair shop.
Motherboard looks like this:
http://img.diytrade.com/smimg/1234834/33807869-146701-0/650D_T4i_Main_Board_PCB_MCU_Mother_Board_For_Canon_Camera_/8aa7.jpg
This is a replacement instruction:
https://www.ifixit.com/Guide/Canon+EOS+Rebel+T4i+Motherboard+Replacement/25261
You may be able to order a spare motherboard by Canon support channels and replace it.

This happens with both cards formatted with NTFS?
If so: It looks like your SD-card slot is wrecked.

Insert card into cardreader and format it using NTFS file system.
Insert card into cam again and startup.
You will be asked to format the card inside the cam. Do this.

Is the cam starting if no card is inserted?

Paul: Top of page -> Downloads -> Browse Nightly Builds -> 550D.109
Download it.
Extract contents.
Delete Autoexec.bin and ML directory from card
Copy extracted contents (ML directory + Autoexec.bin) to card
Insert card into cam and startup cam.
Results?

I'm totally p****d about those outdated and misleading tutorials.

Magic Lantern Forum -> Magic Lantern Releases -> Camera-specific discussions

I have no idea what you are talking about.
First: If ML is running on the card the default option to format the card is keeping ML on it.
Second: There is an ML nightly build for 6D.

Please explain what your problem actually is.

There is only one ML version accessible for you.
Maybe you have fallen to the misconception ML may be replacing Canon's firmware. It is not. Top of page -> User Guide -> FAQ

Rob Galbraith's site is unsupported since July 18, 2012. And there is a date stamp March 31, 2012 on the page you linked.
These data sets are outdated now.

http://www.magiclantern.fm/forum/index.php?topic=12630.0
And read 5D3 specific topics. There is a performance discussion and 1.2.3 is suspect to being slower/less stable at high data rates compared to 1.1.3.

You can use it in 5D3 to load ML and record to CF. You can use it in 6D up to about 41 MByte/s.
Total waste for such a powerful and expensive card.
Only when inserted into UHS-II cardreader it will transfer data to computer fast as hell.
http://www.magiclantern.fm/forum/index.php?topic=6215.0

Insert it into cam.

SD interface in 5D3 is limited to about 21 MByte/s. And it's in no way UHS-II compatible. Your card will be used in UHS-I mode (if any) and all the benchmarks shows that UHS-I with this card will just go around 45 MByte/s which is well below fast UHS-I cards.
Anyway: As time of writing there is no ML supported DSLR with UHS-II interface and those with UHS-I are limited to about 41. Regardless how fast the card may be able to read/write.

It's up to Canon to make this work (if even possible, though). ML will not mess with Canon firmware.

http://pel.hu/EOScard

How do I get my ML settings off the camera and onto my computer?

Cardreader and copy \ML\SETTINGS directory to computer.

Postprocessing: http://www.magiclantern.fm/forum/index.php?board=54

Remove ML directory and Autoexec.bin from card. Copy extracted nightly contents to card. Try again.
Status now?

Now for something completely different:
Well, I just opened a support issue on Canon's official support site and asked about adding ExFAT support to 7D. Call me a naif but it has been added to some cinema gear via firmware update. And it doesn't hurt to ask ...
So: If you have some time to spend, you may chime in and open your own support issue and ask Canon to do so.

I expect "smother" operation (=less likely to stop when 4 GByte block is reached) with ExFAT in 7D.

Keeping in mind that 1:1 sharpness in raw is better than sharpness of full frame raw... wow.

Samples, please!
Why? Because 5D3 uses binning, other cams (except 7D2) use line skipping in uncropped video recording.