it is possible but not trivial to check each SCR and diode. first you should be positive your battery is in good shape, as battery problems can show the same symptoms.
The tech will need a tool called a "flightsystems handyman" (flight systems is a company that first made these testers available to the forklift industry).
You may save a lot of time and money getting the entire chopper panel removed (be sure to mark the 6 heavy cables as you remove them) and send the entire chopper panel to a re-builder like flight systems.
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.