PS2 slim laser differences

[zzattack]

I've got a PS2 V18 with poor laser, and a virtually new one that I originally installed in a V15 but which I'd now like to move over to the V18. Both are PVR-802W type, but there seems to be an incompatibility. In the V18, the homing switch at the center of the disc doesn't seem to be picked up, the motor continues to be driven and starts skipping. Connectors are inserted properly. Anyone know what causes this and if it can be remedied?

 

[zzattack]

I did find out that the ribbon cable connecting the laser to the main board had one delaminated contact. After swapping the ribbon cable this issue is fixed.