E66: The key of the DVD drive firmware doesn't match the key of the motherboard.
E68: HDD Failed to initialize.
E74: According to Dennis Mooney (Xbox ATG) on the 360 dev forums E 74 is HSIO Calibration failed. (HSIO is that insanely fast bus between the EDRAM and the Xenos core. It needs to be "trained" to be reliable.)
When the Xbox crashes half way loading a game disc (e.g. Due to bad unreadable sectors half way)
- It halts itself to a freeze: The Screen which was active, remains.
- Eject does not do anything
- USB Devices are no longer working
- Wireless Controller does not connect
- Plugging in a USB Controler only lights up Left Corner, and Right Down Corner
- Unconnected Video Out Cable results in red flash, Reconnecting removes red light
- The only way to get your box back is to unplug the power cable
Error 79 has been known during obvious signs of graphic corruption. (Overheating?, Power supply insufficient?)
- Error 79 can occur if the Xbox 360 firmware is corrupt.
- Error 74 can be fixed by disconnecting and reconnecting the hard drive. This would be in contrast to the Dennis-Mooney-Quote.