Según supercard (culpa de ellos si no funciona, yo solo lo cito):
Q: How to recover the LOST firmware? (Just for SuperCard CF, SD & MiniSD version)
A: When firmware lost, SuperCard CF, SD & MiniSD can not boot. Player can not run the firmware upgrade program to recover the firmware. There is a way to recover the firmware.
Before recover the firmware, player should prepare something:
1. A NDS/NDSL console. GBA/GBASP can not be used, because it will reset when plug out the cartridge from slot.
2. A good SuperCard CF, SD or MiniSD. We will be in brief "A".
3. The bad SuperCard CF, SD or MiniSD which need to be recovered. We will be in brief "B".
4. The recover program
"Flashmp.rar" (click to download) which made by Darkfader.
Step by Step to recover the lost firmware:
1. Unzip the flashmp.rar, copy the flashmp.nds to flash memory card.
2. Use "A" to run flashmp.nds. There are some messages display on the down screen.
3. Before press the button, swap "B" into Slot 2.
4. Hold L+R and press Right can recover CF version, Hold L+R and press Up can recover SD & MiniSD version.
5. After press buttons, 5 seconds later, "Done!!!" will appear. That mean it works.
6. Now, the "B" firmware will be recover to 1.52 version. It can work now. Please download the newest full version firmware from Download Page to upgrade. (1.70 is a FULL version firmware)
Sacado de la página oficial de supercard-> FAQ