[SOLVED... kinda]I need help with formatting a micro SD card for Steam Deck ("Format error")

[JolliCreepr]

Yesterday as i'm writing this my 128GB microSD arrived to put in my switch. It was currently using a 512GB microSD and I wanted to use that one for my steam deck (I got the 64GB model).
The downgrade from 512GB to 128GB on my switch was a success and everything works perfectly normal. But every attempt I have done to format my 512GB microSD for my deck has ended in failure.
Each time I format, it says that it's testing the microSD, then it says it's rescuing it, and then it ends in failure as the following message appears:

"Format Error
The microSD card failed validation tests and cannot be formatted. Contact your microSD card manufacturer for support."

But the card works fine on my windows computer (I know Steam Deck runs on Linux). I'm not sure if the card really isn't compatible, corrupted, or there's a problem with my steam deck.
At this point I just feel like getting a new microSD, or just swapping the cards around, but i'm afraid that the deck wouldn't recognise those cards either.
I would really appreciate it if someone could find a solution to this problem.

To save you some effort, below is a list of things I have already tried:

• Formatting the microSD on the Steam Deck in game mode through the settings.
  
• Formatting on my computer then re-formatting on my deck.
  
• Formatting on my phone then re-formatting on my deck.
  
• Formatting on my switch then re-formatting on my deck.
  
• Factory resetting then formatting.
  
• Most of the solutions on this reddit thread

EDIT: So I just swapped the 512GB microSD card back into my switch used the 128GB one for my steam deck, and somehow the steam deck formatted the 128GB one without issue? The 512GB one has been in my switch for much longer than the 128GB one, so maybe that had something to do with it. Regardless, I have a working SD card for my deck now, but I wonder if that fixed the issue with the 512GB card. I might try it some other time.

[Jâbbérwôkkï]

When you format on your pc, you may need to open up disc management, delete the volume on the disc, & then create a new simple volume. Format it as exfat, then place it in your Deck. You will have to format it through the deck once more but it should see it after the windows steps above (unless there's some other un fixable problem with the card.

[PopinFRESH]

JolliCreepr님이 먼저 게시:

Yesterday as i'm writing this my 128GB microSD arrived to put in my switch. It was currently using a 512GB microSD and I wanted to use that one for my steam deck (I got the 64GB model).
The downgrade from 512GB to 128GB on my switch was a success and everything works perfectly normal. But every attempt I have done to format my 512GB microSD for my deck has ended in failure.
Each time I format, it says that it's testing the microSD, then it says it's rescuing it, and then it ends in failure as the following message appears:

"Format Error
The microSD card failed validation tests and cannot be formatted. Contact your microSD card manufacturer for support."

But the card works fine on my windows computer (I know Steam Deck runs on Linux). I'm not sure if the card really isn't compatible, corrupted, or there's a problem with my steam deck.
At this point I just feel like getting a new microSD, or just swapping the cards around, but i'm afraid that the deck wouldn't recognise those cards either.
I would really appreciate it if someone could find a solution to this problem.

To save you some effort, below is a list of things I have already tried:

• Formatting the microSD on the Steam Deck in game mode through the settings.
  
• Formatting on my computer then re-formatting on my deck.
  
• Formatting on my phone then re-formatting on my deck.
  
• Formatting on my switch then re-formatting on my deck.
  
• Factory resetting then formatting.
  
• Most of the solutions on this reddit thread

If you are comfortable in linux you can do the following

Boot your PC using a live linux UFD

Determine which block device is your microSD card

sudo parted -l

Create a new empty partition table on your microSD card

sudo parted /dev/$block mklabel gpt

where /dev/$block is the block device for your microSD card. for example If you need to figure out which block device is your microSD card you can use parted -l to list you block devices and their partition tables. Then use smartctl on each of them to get the model number of the block device

sudo smartctl -i /dev/$block

for example if It is `/dev/sdc` you'd run

sudo parted /dev/sdc mklabel gpt

Make a new partition in your new empty GUID Partition Table (GPT)

parted -a optimal /dev/$block mkpart primary 0% 100%

Again replace /dev/$block with the block device for your microSD card

Create a new filesystem for the Steam Deck within the new partition assuming your block device is /dev/sdc for these examples

mkfs.ext4 -O casefold /dev/sdc1

This is the filesystem type with casefolding that the Steam Deck uses. Now you should be able to remove it from your PC and insert it into your Steam Deck and create a new steam library on it by adding it to your storage. On the Steam Deck using its built in microSD card reader it should be /dev/mmcblk0