I have a set of rather unique circumstances and would greatly appreciate any help. Actually, a few hundred people would greatly appreciate your help as well

Rather recently the DDR Supernova 2 machine in my fair cities only arcade decided to die. Being a moderately technical person I offered my help to repair it and save the arcade a few thousand dollars that they currently do not have to buy new insides from Konami (because that's how Konami fixes things, you ship them the old stuff and they basically sell it to you again at a slight discount)

Interestingly enough, DDR Supernova 2 (and 1 for that matter) run on Python 2 arcade systems... which are Japanese PS2s interfaced with a shit load of external hardware for controling the dance pads and antipiracy measures ect (tell you more about that further down). But at the heart of the machine is pretty much an unmodified Japanese PS2 with a standard HDD kit. The game boots directly from the HDD and all communication with the external hardware is done via USB. The networking cable is just piped into the PS2 as well.

A power supply blew and after replacing it the system is still down. After extensive testing I have narrowed the problem down to the PS2's HDD. The PS2 itself runs fine, you can even play japanese games in it. But when you try to access the HDD it just says "No Data". I put it into another PS2 and it also says "No Data".

Since none of the other hardware was fried I can only assume the power supply died a quiet death instead of a loud one (it supplied less power as it died instead of a power surge.) And the PS2 might have done something funky as it was receiving less power than it requires before it died completely, even if it was just for a second or two. I say this because they routinely shut the games down by turning off the power. In fact the DDR machine has a main power switch on the back.

What ever the cause, this drive is now F'd up. And that is where I need your guy's help. I know that copying the drive from a functioning machine won't work. Either due to magic gate, the security dongle, or both. Somehow I have to recover "this" drive if at all possible. I have been reading up on PS2 drives and the PFS file system. I have a few ideas such as using WinHIIP to scan the drive for errors. But, before I do anything I wanted your guy's input.

(and any idea if HDD Regenerator would work?)