By "fixing" do you mean you adjusted the POT on the GD-ROM without any equipment to check how you were affecting laser output whatsoever?

If so, I can see why nothing improved. You can't just modify the POT on an optical system and expect the results to be positive despite what the internet at large says. Keep in mind these will be the same people who say sugar in the gas tank=death to your engine.

Because fuel filters don't exist.