Troubleshooting Harbinger One - 2015, 9v power variant (D1 removed). lamp executes several cycles then slowly dims to a steady neutral glow (~9v). I've completely rebuilt the whole sub-circuit for the lamp and re-tested voltages, resistors, capacitors, transistors, and SPD1/2 for proper values. Gain/Depth seem to work as does SPD. If I manually ground Q11 base, lamp cycling starts over only to settle to steady glow. So it would seem to be upstream issue with C23-C25. Voltages hold steady from power circuit so am getting enough voltage. Any ideas?
Does it take longer to die depending on where the speed is set -- that is, do the same number of cycles pass before it stops oscillating?
The number of cycles varies by the INT (intensity) pot. lower intensity yields 10-11 cycles regardless of SPD1/2. Higher intensity yields 1 cycle at highest setting.
The SPD1 connection to the PCB was faulty. The PCB was actually damaged, probably during the build. I patched from the SPD1 link to downstream resistor and violla~. Solved. Vibing like a rock star now.