That metal pivot arm is what moves the two slide rails that elevates the laser unit evenly. The reason your laser is not lighting when those are attached is because the laser unit is in the down position.
If you take the top plastic cover off the drive, and look at the lower right corner (BD ROM SLOT FACING YOU), you will see a small PCB with a tactile switch. The Slider arm on the right side contacts that switch actuator when the Laser unit is in the down position.
When the unit moves up, the slider pulls away from the switch and closes a circuit. this allows the BD rom drive to flash the laser and begin spinning the disc.
Sorry about the dust in the pic, it's an old part that I keep around for salvage.
Something is out of alignment with your elevator mechanism. It takes a little bit of toying with to get it in the right position.This post has been edited by MorboTron: Mar 13 2011, 05:53 PM