Router Power Supplies ???

This forum is confusing...I don't understand how to "add to/edit" my original post without seeming to "reply" to someone else's possible answer.So,I'm beginning a new post.

ATT told me that my router (An ATT 2Wire 2701HG-B) had went bad.So,I purchased a new one (An ATT 2Wire i38HG) from ebay.This router would not work either for some reason.An ATT service tech came to the house to test the outside lines.All seemed fine.He came into the house and we tried the old router with the new routers power supply.THIS worked !

So,the tech told me that the old routers power supply had gone bad.That still does not explain why the new router would not work though.Nor,does it explain to me why the old router would not work with the old power supply when the power supply seemed fine.All the lights seemed to work.But,after it seemed to power up and the DSL and the Internet lights began to be lit a solid (as opposed to flashing) green,the router would then begin the whole process of trying boot itself back up all over again.Thus,never allowing an internet connection.

I have looked at the new routers user guide online and it says "The HomePortal®iNID (intelligent Network Interface
Device) system comprises three components: i38HG
(inside unit), iPSU (power supply unit), and i3
812V (outside unit). These components are dependent on
each other and do not have standalone
functions. Using these components
together provide triple-play
service (voice, data, and video) to your home".

So,is this telling me that without all 3 of these components that this router will not work to simply connect me to the internet ? I've never heard of a router like that.And,in fact,the tech had never seen this router either.

PLEASE,everybody.....any input would be greatly appreciated.It certainly seems ridiculous to me to pay $27 (total) for this new router when (it seems) that nothing more than a simple power supply was needed.