Sonic Frontiers Power 1 biasing issue

I just purchased my first tube amp, a Sonic Frontiers Power 1. It is running KT120 tubes. I have installed all the tubes and have three tubes biased properly. The fourth tube initially was under-biased and I could not get the "green" LED light to go out, even turning the bias pot through the entire range. I have since switched the tubes around to see if the issue moved with the tube, but now the same tube location is over-biased "red". Again turning the bias pot through the entire range back and fourth does not make the "red" light go out. I will be calling Parts Connexion the beginning of the week to inquire with them, but didn't know if anyone else has run into this with a Sonic Frontiers. Any direction on what to look for? Being my first tube amp, I am definitely on a learning curve. Thanks, Erik
Emailed Parts Connexion and spoke with Michael in tech. Had me check Ohms on some resistors and I found one associated with the tube socket giving me problems to be bad. I have ordered new resistors and will install tomorrow when they arrive. It should cure the problem.
Replaced the "open" cathode resistor with a new one and everything works great!! Biased properly with no problems.