I'm a newbie to this forum.  I just finished a successful build of an old 5E3 tube amp, now I've taken on my nephews Marshall Mosfet 100 amp repair.  I got a schematic off the web.  All the voltages appear correct.  I followed the signal path to the power amp stage, which begins with a couple of A06 transistors.  The transistors in the pwr amp stage seem to pass the simple transistor test.  Is there a way to test the power output transisitors?  Any ideas on how to find why the signal disappears in this part of the curcuit.  Thanks for any help.
schematic      http://www.drtube.com/schematics/marshall/3210-iss7.gif