I put one in and now the machine doesn't recognize the drive.

I'm gonna just pull it out and use it as an external until I can figure it out.

I opened up the machine again and double checked: ll my connections are good.

There is still no icon.

Same here.

Even tore it apart again to double check my connections.

Running the Apple Hardware Test Disc (v. 2.0.2) that came with the machine hangs up during the memory test (have run both the quick and extended tests).

I <know> I saw the answer to this apparently common problem but can't find it.