booting question very urgent ,please help.

[gameguy]

hi i have the gameshark 2 for the psx2 and a chip soldered.i go to load the game after the shark swap and it locks up after i swap ,at the loading screen.any idea?do i need the ar2 as well??i did manage to get it to work once.maybe im not booting it right.
any help appreciated ,thanx