Thanks for the info!
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PCB#2 (3.3V) is definitely kaputt, I did these tests:
PCB #2
1 ?Connect a 5.6V, 100mA max power supply to the GND and +12V pins.
? ? 1.1 ?VDD should be between 3.0 and 3.3V,?
My VDD: 0.5V
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2 ?Connect LIN_REG_EN to ground
? ? VDD should go low?
My VDD stays 0.5V
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3 ?REDUCE the input Volts to < 3.5V!!!??This is to protect the 3.6V Zener D109. ?Pull LIN_REG_EN low and PWM_3V3 high,?
My VDD goes up to 0.6V
My Lab Supply goes over 100mA
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My conclusion:
You are right, the Zener diode doesn't allow to go up to 3.6V it's nearly shorted.
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Let's hope, that there aren't more components affected.
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Question: where is D109?
It's hard to find on this little board.
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Thanks,
Peter DL4PJ
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