SKR E3 Mini V2.0 Not Successfully Flashing From SD Card

[TreeGuy1234]

I got an SKR E3 Mini V2.0 a week ago. I've been trying to flash it via SD card, and it is not renaming the file to firmware.cur. When the card is inserted, it takes longer to boot, but the firmware does not 'stick'. I don't know what to do next.

[Penatr8tor]

1 hour ago, TreeGuy1234 said:

I don't know what to do next.

What size is the SD card you're using and how is it formatted? A lot of controllers, especially the ones from a few years back like the SKR's don't support large cards and they also need to be formatted with FAT32 (not NTSC). I have an old 128KB SD that I use for flashing.

[mvdveer]

8 hours ago, TreeGuy1234 said:

I got an SKR E3 Mini V2.0 a week ago. I've been trying to flash it via SD card, and it is not renaming the file to firmware.cur. When the card is inserted, it takes longer to boot, but the firmware does not 'stick'. I don't know what to do next.

As @Penatr8tor said, smaller size SD card  (8GB or less), Format as FAT, as well as having the filename all Caps when transferring to the SD card ---> FIRMWARE.BIN

[TreeGuy1234]

Thank you all so much! I tried using a smaller SD card, 128MB instead of 2GB. It works now. I'm so grateful for your help.

[Penatr8tor]

1 hour ago, TreeGuy1234 said:

Thank you all so much! I tried using a smaller SD card, 128MB instead of 2GB. It works now. I'm so grateful for your help.

Nice!

Glad to help.

Feel free to hit us up when you're stuck. For the most part we've all been thru these issues and can get you back on track quickly.

[TitusADuxass]

On 12/16/2025 at 9:13 PM, mvdveer said:

As @Penatr8tor  as well as having the filename all Caps when transferring to the SD card ---> FIRMWARE.BIN

I never knew that about it having to be in uppercase. 

Every day is a school day. 

[Penatr8tor]

On 12/23/2025 at 1:35 AM, TitusADuxass said:

Every day is a school day. 

First thing I learned about computers back in the DOS command line days... Syntax matters. 

A LOT 

[PFarm]

2 hours ago, Penatr8tor said:

First thing I learned about computers back in the DOS command line days... Syntax matters. 

A LOT 

I remember paying the same price as today's laptop for a DOS computer setup 

[Penatr8tor]

10 minutes ago, PFarm said:

I remember paying the same price as today's laptop for a DOS computer setup 

I bought an Everex 386-33MHz with an 80387 Math Co-Processor, 2mb RAM and a 120mb hard drive.

I paid ~$6000 US for that machine in '86. That's ~$17,800 in todays dollars. 

 

 

[Penatr8tor]

@PFarm I still have an old 486 tower with dual 50mhz processors in the garage. CAD capable machines have always been expensive.

Hmmm... I wonder if it will fire up or catch fire. That could be a fun rabbit hole.

[PFarm]

@Penatr8tor At $6000, I kinda figured it was CAD-related. 

[mvdveer]

1 hour ago, Penatr8tor said:

I bought an Everex 386-33MHz with an 80387 Math Co-Processor, 2mb RAM and a 120mb hard drive.

You were way ahead of me, my first computer was a Sinclair ZX1 (1kb of memory). Then transitioned to a Sinclair Spectrum 48 ( Zilog Z80A CPU(3.5MHz) 48KB Ram, 16KB ROM and a whole 8 colours graphics) Loading an storing programs were through a cassette player (you do remember those ) The upgraded to an Olivetti Dual Floppy unit - one for the operating system and another for storage - a whole 360KB of storage on the floppy drive. 

[NikosSprocket]

On 12/24/2025 at 10:30 AM, Penatr8tor said:

@PFarm I still have an old 486 tower with dual 50mhz processors in the garage. CAD capable machines have always been expensive.

Hmmm... I wonder if it will fire up or catch fire. That could be a fun rabbit hole.

OMG! I remember compiling FORTRAN on an IBM PC, 8088 with killer 8087 math coprocessor!

Yes you read correctly, IBM PC with 2 5.25 floppy drives and I had to switch the Floppy disk to the Link binary to compile the obj code!!!!!

Btw about upper/lower case syntax. Even existing UNIX OSes (SunOS, Solaris, HPUX, UNiCOS etc.) were always case-sensitive, but Bill Gates derived MS-DOS (IBM) from CP/M and NOT case-sensitive. As Linux is derived from UNIX, it is case-sensitive and does not allow spaces within a command. As far as I know, most Klipper devices are running some flavor of Linux or custom compiled for embedded Linux hardware. Most commands in Linux/Unix are lower case.

Finally, Microsoft OS (Windows) is a mess these days! AS the MS-DOS kernel was never designed to handle servers, they have injected Unix libraries to it and ......

So today if you want to identify a directory path in Windows 10+ you have to put it in quotes as the spaces in the command line are not allowed!

eg. to show a directory list for Program Files on "C:" drive, you will need to type dir or Dir or DIR (C:\Program Files) 

Edited December 27, 2025 by NikosSprocket

[claudermilk]

LOL, old computer guys talk. I still have the TRS-80 Model I in the rafters (actually ran across it pulling out the Christmas decorations). The old original Mac is up there somewhere too. 

Comparing all those old hardware names vs what a RPi is capable of today along with the price... 

[NikosSprocket]

12 hours ago, claudermilk said:

LOL, old computer guys talk. I still have the TRS-80 Model I in the rafters (actually ran across it pulling out the Christmas decorations). The old original Mac is up there somewhere too. 

Comparing all those old hardware names vs what a RPi is capable of today along with the price... 

You said it!

I am ashamed to mention the price I paid for that IBM PC with two 5.25 floppy drives............ 

For the younger readers, PC clones (8088) and components to put one together did not exist then!

Edited December 30, 2025 by NikosSprocket