Can't make RGH 3 DVD drive work

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Hi,

I was rgh'ing a 16go corona when I lost the nand backup. So I created a donor nand and patched it with my original DVD key & osig (i took a picture when xell first booted).
But my DVD drive still does not work... I set PAL, correct OSIG and correct DVD key in Jrunner -> Patch nand then write nand...

Then I managed to find my original nand backup somewhere !!
--> i flashed it RGH3 : drive does not work
--> i flashed it retail mode : drive does not work...

At the end i've picked up a dvd drive that i'm sure work 100%, patched the nand with correct OSIG and dvdkey and flash it RGH3.. still does not work...

I think i am missing somtething... can you help please ?