Hi All,
Recently i bought module T-A7670E/G/SA to try it and notice when using the battery SIM module not working, i measured the voltage input to SIM module and it 0 when using battery, even 3.3v is delivered normally to ESP.
and when using USB voltage to battery is 3.9 normally.
is there a problem with step up converter.
also noticed these caps are missing from the board i have, are they affect on boosting.