Re: BA41-0938A PTC BOARD Model XIDAN-14 Rev 1.2 need help
We may get thrashed for this but let us force the ENTRIPx levels to be ON.
Remove the mosfets that drive these pins.
Then with a piece of wire, mate each ENTRIPx pin to the 3 volt LDO output that is working.
This will mimic what the KBC is supposed to do but I am not 100% convinced this is the order of operations. The fault could be a defective TPS51125 itself.
The key concern again is that, from where does the logic '1' (3v3) originate for these enable signals. The mosfets are only mating the pins to GROUND if the mosfet is ON. If the mosfet is OFF, the ENTRIPx pin is floating - so no logic '1'.
Start with removing one of the driving mosfets and measure the voltage again on the signal line for the ENTRIPx you are testing. What is the voltage without the mosfet ?
We may get thrashed for this but let us force the ENTRIPx levels to be ON.
Remove the mosfets that drive these pins.
Then with a piece of wire, mate each ENTRIPx pin to the 3 volt LDO output that is working.
This will mimic what the KBC is supposed to do but I am not 100% convinced this is the order of operations. The fault could be a defective TPS51125 itself.
The key concern again is that, from where does the logic '1' (3v3) originate for these enable signals. The mosfets are only mating the pins to GROUND if the mosfet is ON. If the mosfet is OFF, the ENTRIPx pin is floating - so no logic '1'.
Start with removing one of the driving mosfets and measure the voltage again on the signal line for the ENTRIPx you are testing. What is the voltage without the mosfet ?
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