can i measure voltage in a tube amp with the speakers disconnected? power tubes removed? one tube in the right output is glowing almost as bright as a light bulb. it's a stereo amp so i believe i can compare left and right and come to some conclusion. there is a resistor that looks a bit like it was overheating but measures correct resistance, i thinking when it's on, it breaks down...possible? the amp still works for a minute then the tube starts glowing and then the amp makes random popping/crackling sounds.
in the attachment, the tube that;s glowing is v7 in the output section page 1. the resistor is r116 on page3.
thanks for looking, frank