[Amps] Checking Power FET's

[Mike & Becca Krzystyniak]

Gretings Amps Guru's,

     I have a HF PA with a pair of SD2931's and I think they "popped" due to
a parasitic while tuning at low power.  I'm not sure of the failure modes
for these puppies and I am looking of a short checklist of what to measure
before trying to rip and replace the finals.  Or maybe there a website with
troubleshooting tips for power FET amps?  

   Any thoughts, guideance, leads, or suggestions would be appreciated.

Thank you in advance.

73  Mike K9MK