Further to my prob with an install into a v5 PS2, (see thread here)
http://www.fileforums.com/showthread.php?t=65481
It turns out that I'd been supplied with the Homebrew version of the chip, it's the same chip but it just doesn't come preflashed.
Instructions for flashing the chip are here
http://www.infinitymod.com/cgi-bin/m..._instructionhb
If your Infinity installation doesn't work, try the procedure before you start resoldering etc. as it could just be that you've been supplied with a Homebrew. It could save you a lot of wasted time and effort.
Regards,
Col