Well thankfully, that’s over and done with. This has taken more man hours than I would have liked. After sorting out the bias faults, all we had to do was to replace some P-Channel MOSFETs. The replacements from ASWO arrived, but were found to be either incorrectly marked as they appeared to be N Channel and or were dodgy Chinese counterfeits. That’s why I always buy from reputable sources. This time, looks like both ASWO and I were tucked up. Searched high and low for a near match and ordered some replacements. Thankfully, these were good and we are all up and running. Moral of the story, ALWAYS test new devices with a good device checker. Saves time, money and smoke inhalation.