Today, I found that Xbox 360 doesn't recognize the HDD. it has genuine HDD from Microsoft. So should be recognized.
First, I checked HDD if it works properly. I unplug it from Xbox 360, then connect it to PC.
On PC, it recognize the HDD as "normal" HDD. And checked sector 16-22, I found that it "zero filled". So my conclusion at this moment is Xbox 360 doesn't recognize HDD because of it's firmware is disappeared.
You need to download below items to repair.
HDDHackr : firmware(sector 16-22) write tool. Which can work on MS-DOS
hddss.bin : firmware image should be located at sector 16-22.
vfd : Virtual Floppy Drive, I use this to create the "virtual" bootable floppy disk.
HP USB disk storage format tool : USB disk format tool. This can install MS-DOS system from bootable floppy disk.
Steps are below.
1. Install vfd and HP USB disk storage format tool on your windows PC.
2. Run vfd and create new image. then mount that floppy drive as "A" drive.
3. format "A" drive. You need to choose option to transfer MS-DOS system (make it bootable)
4. plug USB-disk to your windows PC. then execute HP USB disk storage format tool.
5. format USB-disk and choose option transfer MS-DOS system. Here you need to choose floppy disk, which you create as bootable MS-DOS disk at step 3
6. download hddhackr and hods.bin. Extract them, and copy the extracted contents to the USB-disk.
7. Connect your Xbox HDD to your operation PC.
8. connect USB-disk to your operation PC. Then boot from USB-Disk. Expectation here is boot up as MS-DOS system.
9. Execute hddhacr. Then you could see the list of HDD. Please choose the HDD which you want to use it on the xbox 360.
10. You need to choose "F" to flash firmware to 16-22 sector.
11. choose hddss.bin file to be flashed. And choose undo.bin as a recovery file.
12. After succeeded to write operation to HDD, you can turn off the PC.
13. re plug your HDD to xbox 360, then turn on.
14. At this moment, HDD is recognized as "unformatted". So let's choose and format. Then recognized as normal.
Basically that's all. Then your xbox could recognize HDD again.
To be continued.