Silly question about a KSA 250-Fuse

Did you push it in and turn it?

Yep tried that, still won't budge. Thanks for the tip though. 

From the user manual..............................................................................

  G. WARRANTY AND SERVICE INFORMATION There are no fuses or user-serviceable parts in the KSA-150 or KSA-250. Both amplifiers have a limited warranty of five years from the date of purchase for parts and labor.