Problem with matrix infinity install into v9 PS2

[ottoman]

Have just installed a Matrix Infinity into my V9 PS2. When I flashed up got an really loud buzzing/clicking sound.

Fearing for the life of my ps2 (Romeo Mod carried out) I removed the chip and tested again to see what was going on. Still getting the same buzzing/clicking sound without the chip installed.

Took top off and top of dvd drive off and watched laser when I switched on. The laser is travelling to the middle of the drive but not stopping and moving back when it hits the microswitch at the centre. Instead it just keeps trying to travel further and the plastic teeth on the side worm drive are slipping causing the buzzing/clicking sound. After a while (about 4 secs) of the noise it gives up and will then quite happily boot a CD or DVD no problem. Its just that initial switch on/off or hitting reset.

Any Idea what could be causing this?