New laser damaging discs???

I had a 360 with a dead (BenQ) drive. I replaced the optical pickup assembly with a new one and the console worked fine for a couple weeks. My son then complained one day that it began making loud noises. He ejected the game he had been playing and found that the laser lens had been driven up into the disc creating concentric scuff marks on the disc.

When I replaced the optical pickup, I did not make any pot adjustments. Could this be the cause? I still have the old pickup, so would it be simply a matter of reading the values from the old pots and setting the new ones to the same values?

Thanks,