I bought a broken 360 from eBay, I don't know anything about its history. It had the 3 red light error, which I've fixed with an X-Clamp replacement, but then found it had trouble reading disks. It's got a Hitachi 78FK drive - the mechanism seemed to be broken as it wasn't closing properly, so I decided to put a spare Samsung MS25 drive that I have in its place.
Managed to get it to read the Slax disk and into ModeB ok, got it detected in Windows and dumped the firmware fine.
Using Maximus Firmware Toolbox I loaded up the firmware originally from the Samsung MS25 and replaced the key with the one from the Hitachi firmware. Then went to Tools -> Spoof Firmware -> Hitachi GDR3120L ROM 0078 (with Master Checksum selected beneath) and hit Apply Spoof.
Then I swapped the DVD drives in the 360, booted from USB and applied this new, spoofed firmware to the DVD drive.
Results - the 360 boots to dashboard fine, plays movies fine, but when I insert a game (original) it plays it as a movie, giving the 'To play this disc put it in a Xbox 360 console' message. The firmware is not hacked, nor do I want it to be, I'm just trying to replace a broken DVD drive.
What could be the problem here? Bad flash? Perhaps a bad dump from the Hitachi drive that got the key wrong? (Doesn't the fact that it boots to dashboard mean that the key is right?) Have I missed something with the spoofing?