I hate to bump an old thread, but there's a lot of good information here and I'm having the exact same issue with my Wii. Since this issue seems to have gone unresolved as far as I can tell, it seems like a good idea just to post my issue here so any old information can be referenced.
I can load apps off of the SD card just fine, but if the SD card is inserted at the same time as the hard drive and I try to switch to hard drive as the source in the homebrew channel, it just loads the apps on the SD card. If I remove the SD card and try to switch to hard drive as the source in the homebrew channel, I get the same DSI dump screen that you do. Did you ever find a solution to the problem?
Notes:
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1. I am using a WD Passport 2TB drive formatted in Fat32 with 32 KB cluster size.
2. My drive has a single 2 TB partition. (I've considered making a separate smaller partition for the apps, maybe that will help?)
3. I modded my Wii using letterbomb on 4.3U, then installed bootmii and priiloader.
4. I installed the following cIOS:
a. cIOS: v10 beta52 d2x-v10-beta52, cIOS base: 56, cIOS slot: 249, cIOS version: 65535
b. cIOS: v10 beta52 d2x-v10-beta52, cIOS base: 57, cIOS slot: 250, cIOS version: 65535
c. cIOS: v10 beta52 d2x-v10-beta52, cIOS base: 58, cIOS slot: 251, cIOS version: 65535
5. I have one of those gamecube compatible black Wii consoles.
6. USBLoaderGX and WiiFlow reads the games from my hard drive just fine.
Let me know if you need any more information.
EDIT: This is the exact problem I'm having (not my vid but same exact issue) -
Edit 2: I think I found a solution thanks to a kind redditor and a post from here, which unfortunately I can't link since I'm a new member.
the problem is that programs like GUIFORMAT use GPT partitions, but we want MBR for apps like The Homebrew Channel and emulators to detect the drive successfully. You can use something like Minitool Partition Wizard or similar to convert the partition from GPT to MBR.
- Download Minitool Partition Wizard (use google)
Note: Be sure to uncheck avast in the installer as it's bundled in by default!
- Open Minitool and choose 'Disk & Partition Management'
- Right click the Wii Drive in the list and choose 'Convert GPT disk to MBR disk'
Note: Make sure the partition with your games on it is marked as the primary partition after converting the disk to MBR.
- Click apply and follow the on-screen prompt.
- Done! I've done minimal testing but FCEUGX and The Homebrew Channel now shows my drive perfectly!
This should not cause any data loss or problems, but obviously I take no responsibility for any issues this might cause. It has solved my problems.