Just a little dust.. I found the inside of an Agilent 33120A looking like this. It runs a little warm without being covered in a blanket of dust! No wonder the output amplifier failed. Share this:Click to email this to a friend (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Google+ (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)