[Amps] AL-1500 troubleshoot relay???

[James M. Daly]

I have a sudden issue with my AL-1500 which will not go into transmit. 

1.) Turn on power, amp starts up and all appears normal through the timed
warm-up. 
2.) After appropriate timed warm-up Plate meter lights as normal; but there
is no loud click from a relay in the case as I would normally hear. 
3.) Move rocker switch to from STBY to OPR and key down; XMT light on amp
blips on for a fraction of a second and grid meter bounces ever so slightly,
but then nothing, no XMT light, no response. 
4.) Subsequent attempts at keying down produce no response from the amp at
all. 
5.) Turning the amp off, waiting a minute and then turning it back on leads
to the exact same cycle of events. 

I must admit while I'm able to understand principles I have no practical
experience with amp repair, so any help trouble shooting this problem or
pointing me in the right direction would be much appreciated. 

Thank you, 
James M. Daly - AD1L