I am trying to fix my sister-in-law’s optical drive in her Compaq Evo N800v laptop. The drive is an HL-DT-STRW/DVD GCC-4240N. The problem is that it doesn’t read discs of all kinds. It just spins up, makes noise and then nothing. Not only can the user not use it with software, but I was unable to boot off of it (using my Windows disc). The DMA is enabled and I have found firmware from rpc1 that I would like to try before I replace the drive.