I just bought this 160 GB one from amazonThe network adapter was this oneand it came in an unopened original box.I have not had any problems. If you connected it to your computer and it worked fine for formatting it is probably your network adapter or PS2 that is having an issue. Assuming your network adapter is new do you know the history of your PS2? I have only been able to get HDloader to load from USB and I used the latest versiong from SKS apps that state it has God of War and GTA compatibilty. Also I had HD loader format my Hard Drive, I put it in just the way I got it and it detected and asked to Format. Oh yeah and my hard drive has some lights I can see flashing through the vents on my ps2. Just a heads up I just got a used Network Adapter for under $2 through gamestop.
I just got one for my buddy's PS2. Just request a store pickup through their website.It is working fine.
I would think your issues is a bad adapter since the drive works according to the compatibility database and it works with your computer. The PS2 connector is probably fine too since you had not used it before and the one review on your amazon link mentions it was used and dirty when he got it.
You did tighten the screws when you tried it right?If you start HD loader with no drive does it freeze or give you an error message?If you know anyone with a PS2 it should be pretty easy to pop it in and see if it works on their console.I could not figure out how to get Winhiip to format the drive, I used HD loader to do that.