[Amps] Alpha 89 ALC question

[Floyd Sense]

Please - this is a simple technical question about the Alpha 89. No 
lectures about the evils of using ALC, etc.

I recently acquired an Alpha 89 amp from the original owner and am 
checking it out thoroughly.  The only problem I see is that no ALC 
voltage appears at the ALC jack on the rear panel, regardless of the 
setting of the rear panel ALC pot.  It seems to me that the ALC voltage 
is developed by U1C on the power supply board and that it's based on the 
grid current which must be measured between the -HV rail and ground.  
(Haven't been able to discern exactly where that is sourced in the 
schematic).  At any rate, the grid current monitoring obviously works as 
the Grid Current LED meter reads properly.  But, no ALC voltage at all 
with grid current showing up to around 100 ma on the meter.  I would 
think that I should see a gradually increasing ALC voltage (in the 
negative direction) as the grid current increases.  Can anyone familiar 
with the circuit comment?  Thanks for your help.

73, Floyd - K8AC