I had an issue with my TX2. It would loose power at random and then won’t come on until leaved with power jack disconnected for some time.
I have found C176 was leaking some current and that in turn was triggering VIN_PWR_BAD_L signal.
So I removed C176 and that fixed the problem.
If you have power problem on your carrier board, check voltage on Q31’s 3rd pin (drain). It should be close to 5 volts for normal operation.