Hi all first time poster. I have a marantz pm17 mk ii ki signature amplifier. I dont know much about it or its worth as it seems hard to find info on it bit by the weight and feel of it it seems quality. the main question I have is that the temperature gauge seems to be rising towards the top end of the gauge is it supposed to or what is the unit meant to run at. would it hurt to open up and give it a blow out of any dust that may have accumulated inside.