I just soldered my AirGradient basic and the Oled screen isnt working at all and only the Co2 sensor can be recognised and gives readings.
Please send more photos from both sides of the board and close ups from the components. Maybe we can spot something.
I think the OLED display might need to be rotated 180 degrees.
I have already tried that, I was just trying to try another way but forgot to turn in back to normal before taking the pics
Can you run an I2C Scan and see if it detects the addresses from the SHT and display.
Also maybe try with a different power adapter.