Hey, I just replied to ur other post. I measured the voltages on the pins of the 12ax7's. they are ok. Man, I wud love to solve this issue with my half drive. Question: On a cold power up, shud all of the voicing led's be off? Oh , on your other post, the same happens to mine ( while all 3 are on, 1/2 drive is dim, then after a while brightens). With ur post here, my half drive seems stuck when first powering up but never have lost it. (sigh). Thanx for the reply, James.