Can I do a meter check on amplifier on yamaha yst sw 800?

I have a yamaha yst.800 home theater sub . I want to know if amplifier is bad or board is bad . Anyone with lots of experience with yamaha subwoofers please can you help me figure this out . On my sub when I plug it in I have a green light, even checked subwoofer speaker and that works .Im hoping that it is a fuse on the board itself . can you help?