[HomeBrew] dentron GL-1000 no grid output

[ni4l]

Hi 
I have picked up a orginial no mods Gl-1000 it has a plate voltage of
1100
volts on the plate. the swr between the rig and amp was checked 1:5:1
have a mn2000 between icom 751 and amp but since swr was ok just left in
thru mode. 
when i flip swith to current it does not move.
when i flip to rel output and tune on it plus the adj in back for rel
output it shows around 4-500 on top scale but amp is producing no output
have drake w4 in line after amp shows 0 output. was checking on 3.919
since it is the only resonate wire antenna i have up.
any help on this would be greatly appreciated.
chris NI4L