A Q about v4 and v6
 

Ok, so if thought if a ps2 was 30001R then it was 5 or 6 and you could tell based on that little extra screw. Someone said that a 30001R could be a v4? How would you tell the difference between a v4 and v6? v5 is obviously easy. But thanks.

Ohyeah
Woot Woot Holla Holla

If it has a R at the end of the SCPH number, and it has the extra screw in the expansion bay, its a V5 or V6.... Only difference is a connector that is upside down..........

If it has a R and does not have the screw, its a V4......

This applies to NTSC/US PS2's.... Unsure about PAL versions....