A simple blown fuse will render an amp unable to power on, is it blown? Many suspects to investigate before jumping right into testing for bad power transformer. If fuse is blown then transistors or a bridge rectifiers top the list of suspects right off the bat. You got a schematic for this exact amp? Sure we can test the power transformer but first just have to ask if the fuse is intact. A bad transformer will surely take out fuses but many other things to consider first. If no fuse blown then it might a problem that deals with simple power connections or switches.