To check if you have the V10
If have a USA/CANADA SCPH-50001 AND if you can find DATE CODE 3D as shown below, you have a V10 PS2 main board (GH-026 board).
SCPH 50001 / 50010 Date Code 3D is a V10
If have a PAL (EUROPE/AUSTRALIA) SCPH-50002/3/4 AND if you can find "a" as shown below, you have a V10 PS2 main board (GH-026 board).