Marantz power switch repair
This is my response to an old forum question, but maybe it will help someone since the search engines are pretty good now.
The Marantz push button power switches are notorious for eventually being the first part to wear out. If you are willing to try repairing your own, I've got some good news. The old 22 hundred series Marantz receivers and amps used a variety of switches made by Matsubishi that are built to last, but they contained a fatal design flaw... two miniscule ball bearings intended to provide added life to the moving parts. They have now done their job, having protected those moving parts for thirty years, but now they have worn a path for themselves to move out of position and jam your switch. The rest of the switch is still good, although when you take it apart to remove those ball bearings you may as well clean the contacts on the rocker arms while you're at it. The factory sealed the ESB-1130-33 series switch boxes by spreading two metal flanges over the plastic cover panel. You can use a needle nose plier to sqeeze them together and then to bend them away from the cover to allow the cover to lift off (after putting it back together just use the pliers to bend those flanges back towards the cover plate to hold it in place for the next thirty years). Study the placement of the parts as you take it apart, because nobody is going to tell you how to put them back again. The trick is, get those ball bearings out of the switch and reassemble it. That's all there was to it.