Looking for PS2 HDD SCPH-20400 information

[TheTinWhisker]

Hey everyone,

I recently got an SCPH-15000 PS2 from Japan. I also got the SCPH-20400 External hard drive with PCMCIA adapter.
I will be using Free Mcboot with this setup to launch games from the HDD.
As of right now, Free Mcboot doesnt load, which im sure is due to missing a kernel patch from the HDD utility CD which is on the way.

I have a second SCPH-20400 hard drive on the way as well. My current 20400 hard drive does not power on. I have read online that it blows a fuse alot. I cannot find any information on the board inside the 20400 and how to troubleshoot it and what component to replace.
There are no schematics I could find as well.
Im good with soldering and replacing parts, but I dont know where to start with the toubleshooting to identify what is bad.
Does anyone have any ideas?