Lately I've been noticing some uneveness in engravings. Attached is a scan that show's what I mean, it's engraved on black laminate with a white cap. It's not a big issue for us yet but in the red circles you can see lines of white in areas that should be smooth black, I've looked through the forums and seen this attributed to low tube power and alignment among other things, I've found the instructions to align the beam and will try that on monday but I'm doubtful for some reason. We've had the machine for around 5 years and it's normally only in use 2-3 hours each day, any help is appreciated