TX2 carrier with power loss issue fixed


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.

C176 related circuit is to release VIN_PWR_BAD_L surely after VDD_IN is stable. If remove C176, the timing is not guaranteed. You can try removing R95 instead of removing C176.