I have a 1995 kobelco sk150lc Mark III, and the digital board that gives the fuel level and temp just has a bunch of black marks on it. It did work for awhile saying OK and all the other things, but stopped and started doing this. Sometimes you may run the machine for a couple of hours or so and than it will start beebing acting like it wants to work. I've pulled it all apart looked it over sprayed all electrical connections and still no luck any advise?