[TenTec] Centurion amp no output, was working

[jkauppila at tutanota.com]

I mistakenly transmitted from my Kenwood TS-590S into my new (used) Ten-Tec Centurion amp without the control relay turned on in the radio.  The amp saw up to 20 watts in with the amp switch in operate with no transmit relay signal from the radio.  Now the amp has no output.

Notes:

Amp turns on, standby, operate and transmit lights works.  There is plate voltage.  The tubes light.  There is plate current and grid current when I transmit from the radio with the radio's amp control relay now turned on, but no output from amp.  I only tried transmitting with low power from the radio, up to 25W.

Could I have blown a component on a board transmitting into the amp when the amp switch was set to operate with no control signal coming from the radio?  If so, where should I look in the amp?

Thank you for any suggestions.