T-Beam Supreme only powers on with USB
I've recently recieved a T-Beam Supreme (M) that will not power up when on batter power.
I've used the pins to check voltage, and I have
- 4.19v on VBAT to GND
- 0v VBUS to GND
- 0v VSYS to GND
My electronics knowledge is quite limited, are there further troubleshooting steps I can take to identify the issue?
Thank you in advance for any suggestions and assistance
I have not edited the firmware, the device is running v2.2.11 of the Meshtastic firmware.
@chaosaffe So, as I thought. hmm...Some LilyGO products need a special power on GPIO to be set, in order to get Battery Power. It stumps most people, including me, until someone figures it out!
Since you run the shipped-firmware, it can't be that.
It is very hard to even find a schematic for these, I'v been trying since yesterday.
I'll keep digging.
Please check here again for any updates.
I don't think '0v VSYS to GND' is correct and maybe the answer, IF either of us can find a schematic!
P.S. OK, this might be it:
Here are some salient points.
The Power ON key to the APX power supply chip
And its hardware switch:
@chaosaffe This just posted by another user:
@teastain2 Thank you Terry for taking some time to investigate!
Unfortunately the schematics are a bit above my head. Are there some pins or components on the board that you're recommending I test?
I should note that the device does not seem to recognize and charge the battery when it is installed. I am suspecting a hardware issue at this point, but would like to confirm.
Can you measure the voltage at this point? Please connect the battery and measure the voltage at this point in the picture to see how much V it is.