SOS MY XBOX 360 SLIM WILL NOT TURN ON

So will the xbox 360 slim 4gb take a hdd from a xbox 360 slim 250gb? And is the only differences the cases and the hdd capacity in the two slim xboxs

I went to a Gamestop and bought a newer used Xbox 360 Slim to test if it was just my console going bad. The same issue happened on the Slim so it's not just my console. And even then, plenty of the responses to this forum post are from people who I've noticed
mentioned they had an Xbox 360 Slim. So my console being old isn't the problem. I returned the console once I found out that wasn't the problem.

It's not r-e-a-l-l-y fat the console. They made it that way so that it would get more than enough proper ventilation. It is slightly bigger than my Xbox 360 slim though. I first joined Xbox when the Xbox 360 Slim 250gb glossy black console came out in my
country mid to late 2010 (NZ). And Xbox 360 came out 2005 so had to wait about 5 years for a slim version for that gen. They might make a slim version of it but expect to wait probably at least another 2 years for one. It weighs about the same as my 360 too.
The design isn't a huge fuss for me even though I wish they'd made it no bigger than the 360 slim console. It looks like a VCR because it has like a Windows 8 style to it, sharp edges and clean lines.

so ermm, guys question:

Does anyone know where i can get an Official Xbox 360 250GB hdd drive for my xbox 360 4gb slim? i want to play Halo CE & Starwars Battlefront two again on backward compatibility on the xbox 360 4gb slim

(a Direct link would be VERY appreciated)

How do you transfer stuff from a xbox 360 slim 250 GB HDD.. to the le gears of war 3 xbox 360 slim so do you do that on a thingy or something all i need to transfer is my profile on to that xbox what do you use anyway and how!