[Elecraft] k2 agc

[Stokest977 at aol.com]

hi
 can anyone on the reflector advise  with this agc problem
have instaled new control board
volts setting with r1 no problem sets to 3.8
fast and slow positions work fine with s meter acting normaly
when i go to agc off audio goes dead bar on s metre goes full
scale
 volts checkes on controll board front panell removed
u1 and u2are all corect
 
any advise where to look
                              thanks
                                   tom g0lne