I have a FTdx5000 unit on my service bench for no power on issue. Power supply is ok. Power switch on face of radio is sending a positive voltage to the CNTL board on the PSW line to the Q4552 CPU, pin 87 as expected. No logic output change (0 VDC) on the PON output pin 40 on the CPU. I would expect a positive voltage on that pin, while front power switch is depressed, to energize the power on relay RL5515 on the PA-B circuit board. Replaced the CNTL board with no change in functionality. Looking for anyone who has had this problem or can guide me as to what I am missing. I assume that the CPU is not seeing an enable input from another circuit board to gate the power on circuit for power on.
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