thanks chedabob, now i can post a full pictorial
so as i said before - what you have is a hard disk that doesnt even start up when the xbox starts up - you can listen closely to it or even touch it when you start the xbox and hear/feel nothing (warning this can result in elctroshock and you can die).
what you want is a hard disk similar to the one you have - i was lucky - my friend had the exact same hdd (btw: his xbox was 1.5 years old and my brothers xbox that was bought a week after mine had a diffrent model) note that i belive that it might work with hard-disks that are close to the one you have... (same manufacturer and same back panel at the least )
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note that the serial number will never be the same but with me and my friend's everything else was - quit amazing...
you will also need a star head screwdriver - i tried using diffrent types of screwdrivers and i "screwd them up" (pardon the pun).
anyways if you have all that the process is fairly simple:
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you see the little yellow circles i put there? these are the screws you need to remove which will result with you having the back panel (circuit board/electronics)
removed and in your hand...
now what you should do is place the defective circuit board aside and do the same process of disconnecting the panel on the hard disk that DOES work - and connecting it in it's place on the formerly deffective disk - and of course connecting the screws...
you should now connect the disk to the xbox - and it should work...
(i apologize if the quality of this guide is low - it's the first one i've ever written so i'll welcome any type of criticism)