How to bias a tube amp with a Multimeter

@freediver yes I’ve tried turning each pot, and still no reading on the MM. I’m afraid I have to take it to a technician, which means a 45 minute drive each way. Oh well!

On your multimeter, make sure the black lead is in the COM jack and the red one is in the proper jack for measuring voltage.  On some meters there are different jacks for the red to be inserted in depending on the function you select.  If your meter has only one input for the red probe, then that would not create problems.  If there are two input jacks for the red probe, be sure to select the correct one.

Yes, probes are properly connected. 
 

I was just quoted $130 to bias the amplifier. But I’d have to wait 4 weeks to have it done because of other jobs ahead of me! Argh. 

Paying to have the amp biased won't help you in the future..For that much $ I would want at least a diagnostic of the test point problem included..
 In the mean time,I would run the amp & see how it sounds..If it was properly biased before going into storage,there's no reason to think it's drifted off much..
I might also consider buying another meter,I mean $20.00 for another meter that can be returned is a lot faster & cheaper than the alternative..Good luck..

@freediver excellent points all around. I requested a later tech I contacted that I’d need to be instructed how to bias the amp from the bias points. He accepted that. 
 

Since I don’t have a manual, and haven’t found a pdf on the internet I’m kind of at the mercy of someone who has knowledge. I’ve been running the amplifier for several hours without any runaway tubes, but don’t won’t to run the risk of having that happen, and simply operating the amp without knowing the status of the current bias seems a bit foolish.