I have Perfect Pass system in a 2004 Prostar and the on/off button no longer works. Fortunately the system is stuck on so I can still use the boat. I am told the membrane behind the display is the problem and it is no longer available. I am looking to buy a new gauge or something other than the $840 upgrade to move to GPS based system. I am not finding anything on eBay. Does anyone have a gauge for sale or know of a company that would have a gauge or parts for sale?