Just wondering if anyone has suggestions for quietening/silencing the fan on the KRP-500 input box? I'm thinking I might just need to vacuum out any dust and what-not, but is there anything else I should do? Ideally I'd like it to be completely silent.

I recently picked up a nearly-new KRP-500a and of course I'm delighted with it. My only gripe is that 4:3 content appears with grey sidebars (aka "side masks"). I know the reasoning behind this, but I really want to change those bars to black. Although not the same model, I stumbled upon this YT video showing someone doing exactly that by going into the service menu: https://www.youtube.com/watch?v=RILUDxBvqNI So my question is: is this possible on my KRP-500a? And if so, how?