I can plug in the USB cable and get the red charging LED. Wait for it to fully charge. Turn it on. Now if I unplug the USB cable everything turns off. Plug the USB cable back in and its on again. Tried two different batteries that work just fine with my Pico Lipo.
It remembers what state it was in. If it was on when I unplugged the USB cable, it turns back on when i plug it back in. If it was off it stays off. Will not turn on if USB cord is unplugged and only the battery is connected?
Looks like its an intermittent fault. It will work normally then just decide not too. Checked all my soldering, even reflowed a couple for good measure. It’s not that though. When it decides to not work the Power LED doesn’t come on. Not until I plug in the USB cable. Charging LED then comes on. Both go out when I remove the USB cable.
Running the Pico Lipo battery example. When its working correctly it shows 4.22V, 100% when running on Battery. And Charging when the USB cable is plugged in.
Part of the circuit is working correctly, it remembers if it was on or off, it just refuses to actually run off of the battery when it fails.
I’m thinking its the vsys & vbat switching FET?