All the lights except for the blue pilot light in the centre fade out when you power it off and go into standby.
When you power it on from standby, the 3 levels of red "christmas tree" led lights come on in succession. the relays then click and they go back down (simultaneously).
I don’t think there is any way to verify the auto bias circuitry. It is controlled by a computer board.
I had lots of problems with it. It had to go back for service a couple of times in the few years I had it. It would literally go up in smoke Apparently, they were manufactured with faulty capacitors. That is why they were replaced very quickly with the FPB series.
Hope that helps.