If the failed console is not a 1.6, then odds are the other machine won't boot off the modchip... it depends on what's in the other banks. You can certainly try it. Should be no issues if the two consoles are of the same version.
The X2 5035 should allow you to boot again, but only if the HDD is unlocked - if that's not the case, then you will need to unlock the drive. How you do that depends on whether or not you're using the original HDD or not.
If it's an upgraded HDD, then it's very likely already unlocked. If you plug the HDD into your computer,
LiveInfo can tell you whether it's locked or not.