[Elecraft] KPA500 not working

[Gordon LaPoint]

Hi,

      My KPA500 started acting up and now does not amplify at all, and 
the input SWR seems to bounce around.  I did hear what sounded like an 
arc (fairly loud bang, though it was the KAT500, not the KPA500)   The 
KAT500 is still working normal, but the KPA500 is bad, even into a dummy 
load with the KAT500 bypassed.

Any ideas? or just get an RMA and send it in?

Thanks,

Gordon - N1MGO