How to bias a tube amp with a Multimeter

You do have speakers connected right? if not get them connected tube amps do not like to be on with no spekaers/load connected, could damage the amp. 

from the picture i'd say your positive lead on the right or far left test piont, depending on what tube your testing, and the ground to the center. check what range your meter is set to as well you could be out of range. 

I am not familiar with your amp.  I take it there is no button or switch that needs to be turned on to do the biasing.  It appears that the common or ground probe goes into the center test point and the positive probe goes to the test point on either side of the center position.  It is a bit strange that the two positive test points have slots in them as if a screwdriver is suppose to go into that point.  Could it be that the point has to be screwed in before commencing testing?  

Do you have a "low" MV setting on the meter?

Maybe around 200?

If so try that.

DeKay

@larryi yes, and the bias points are so close I can barely get the tips of the MM onto them! I don’t know what to make of the screws,

I tried searching for a manual for the amp with no success.

yes, speakers are connected, and the amp is fully operational. No there is no incremental mV adjustment on the MM

Is it possible the bias pots are adjusted so low there is no flow through them?Maybe try turning the pots up(make sure no signal to amp & volume control turned down) & check again...Other than that,my next move would be opening the amp up & checking the connections at the bias test terminals...