On my Ameritron AL-80B amplifier, it works on all bands except 40m. It appears to simply pass the signal through without amplification. I can make (unamplified) contacts just fine, the needles work just fine, but no amplification is done. It acts the exact same way as when I use it on 20m but have the band selector switch set for 80m. No amplification, just signal pass through. I have opened it up and done a visual examination of the components inside. Everything looks fine. No opens, no shorts, etc. Not really sure what to check out. Any good places to start? I will not be powering it on with the case off due to HV hazards, so any testing will have to be unit off. I could also take it someplace in Seattle to have it repaired, but don't know who might work on them.