When my playstation 1 used to crash many years ago... I take the PS and flip the whole thing on its back so that it is sitting upside-down on the table/ground.
Wait a few seconds then you will hear a faint sound as the system reads the CD, and all of a sudden the game UN-freezes.
I have not tried this trick on PS2 nor do i know how or why it works. Let me know if it works...