After noticing my Acom 1500 not producing full output on some bands (Acom tested good), I went off and started what I thought to be a short TX Gain Cal (which I had never done) to the factory assembled rig. This rig has functioned perfectly since I received it from the factory on 4/19/2011.
I am not going into the myriads of runs on the cal procedure in the latest utility (188.8.131.52) and firmware, as I was very frustrated. I was successful in the 5W cal up to the 60M band where I hit a dead end. I looked thru the dozens of posts and tried all that had something to do with tweaking the computer inputs. No luck. Then, I noticed a few type of mechanical type problems, most I would not try in opening up the rig. I'm too old for that and my ham radio tweaking inside a radio are long behind me (8 years retired and full time caregiver for my wife).
While running a sweep of another TX Gain Cal, when the run was inside the 60M band trying to find 5W (it was good at finding 3.4W or so), I lifted the rig at the front and let it drop an inch, out of frustration than anything else! Lo and behold, the run slowed, showed 5W and proceeded on to a successful 5W cal. I nervously selected the 50W process and yes, you know the answer, it worked like a champ.
Going to bed now (almost 10PM now). I guess there is a loose pwb, component or cable inside? Maybe someone can give a guess at what might be wrong. If it is easy to get at, I could go in and start to tighten screws first, re-seat cables, etc.?
BTW, the rig has never been dropped, etc. always sitting there waiting for the next DX station!