UPDATE: It is now possible to fully UNBRICK the WiiU using a hardmod, teensy and WiiU Nand Tools. I have tried a new approach to dumping the Emmc nand and it has worked. With this method I was able to dump the nand to an img file on the PC and then successfully write the img file back to the WiiU. The trick was to disconnect the CLK signal to the nand on the motherboard and then the pc was able to read the nand. After you have dumped / wrote your nand.img make sure to reconnect the CKL with a jumper. Dumping the nand was the same procedure as with the 3DS hardmod using Win32DiskImager. First connect the SD card to your card reader on your PC. Press the power button on the WiiU. A popup message should appear on the PC saying you need to format the drive. CLICK CANCEL. DO NOT FORMAT THE DRIVE!!!! remember what drive letter it says. Open Win32DiskImager and make sure the Drive letter on the right is the same as the one that popped up! Select where you want to save the .img file and click read. The dump size was 29.7gb and took around 2 hours at 5.7MB/sec If when you click read and it says "Lock Error" keep trying. it could do it on the first attemp or the third or the twentieth. This was exactly the same with the 3DS. To try and eliminate this problem make sure there are no explorer windows open or anything else that might be trying to read the drive. When the read is complete close Win32DiskImager and safely eject the drive using "Safely Remove Hardware and Eject Media" Hold the power button on the WiiU to turn off the console and don't forget to insert the jumper so that the wiiU can boot normally again. PLEASE NOTE this is not a proper step by step tutorial (yet). I'm ony posting my findings and what I did to successfully read and write the nand. If someone wants to write up a more detailed tutorial later please feel free (just give me a mention I WILL NOT BE RESPONSIBLE FOR ANY BRICKS. ONLY ATTEMPT THIS IF YOU KNOW WHAT YOU ARE DOING!!! Even though this by itself cannot UNbrick a bricked system. Its a start. The next thing to try is the TSOP NAND and then anyone with a backup of BOTH the eMMC and TSOP nands should be able to fully UNbrick their WiiU if anything goes wrong.. UPDATE: Not all Card Readers will work. Here is a list of confirmed Working & non Working Readers: Transcend TS-RDP8K - WORKED ALL IN 1 HDD Docking Station Model:875 - WORKED Logilink Cr0001b - Confirmed WORKING. Thanks @Tommy084 Anker USB 3.0 AR200 - DID NOT WORK (would not detect drive?) Kingwin 5.25 inch bay mounted fan controller/multi card reader - NOT WORKING. Thanks @DocAmes1980 UPDATE 2: I've been playing around with this some more and if you also connect the other 3 DAT lines the read rate goes up to 18.4MB/sec (write rate 10MB/sec) so a full 32GB nand can now be dumped in around 30 minutes instead of 2 hours! UPDATE 3: Here is a video of it working. UPDATE 4: I can confirm that the mlc backup made with dimoks' sdio_nand_manager works with the hardmod. I created a new rednand, dumped the nand images with sdio_nand_manager then straight away made a mlc dump with the hardmod and the SHA256 hashes form both mlc dumps match. UPDATE 5: Thanks to @DocAmes1980 & @Tommy084 for trying it out and confirming the mod works.