E71 Error

Pull the HDD off to see if it boots and if so then you will need to find the rouge file or format the HDD in another Xbox

 

E71: possibly a dashboard update error, Check below in the "Console Reset Codes" for instructions. If that does not work there is no other solution and the console must be sent back to MS for repair.

[SIZE=18pt]Console Reset Codes==--[/SIZE]
Clear All Installed Game Updates and Console Cache

1. Go to the "system" blade
2. Select "memory"
3. Press Y on the HD symbol
4. Press X,X, Left Bumper, Right Bumper, X,X
5. A message will appear saying: "Do you want to perform maintenance on your Xbox 360 storage devices?"
6. Select Yes

Clear Any Failed system updates that cause the console to error.

1. With the console off, press and hold the sync up button (the small white one)
2. While holding the sync button press the power button to turn on the console
3. Continue to hold the sync button until the Console has booted up completely.
4. During the boot process the console should clear any failed updates, allowing you to use it normally.

 

Yes, it boots without the HDD

I am sorry I do not understand what you're saying but my console does not boot when the HDD is in. Right now, I am trying to Low Level Boot it and then put it in the xbox and configure it, lets see if it helps.
So I formatted the HDD, configured through Xbox, installed FSD and etc things and installed XBDM.xex and set path in Dashlaunch, restart and the same problem.. wtf

 

ITS THE XBDM.XEX!!!! I HAD THE SAME PROBLEM THE XEX IS CORRUPTED TRY A DIFFERENT SOURCE FOR THE XEX

 

it was the xbdm.xex... got the right its ok now

 

Good to see you fixed it

The X,X, thing is to clear the cache, which is done by going to your xbox hard drive and just pressing Y.