Arrived New but white screen

[Chee]

I just received the package new, and first power up with 9V dc supply immediately gives White Screen.

D1 LED blinked 2 times, 3.3V is good and 1kHz 3.3V square wave is perfect.

Checked all LCD contacts are soldered properly onto pcb.

1 interesting observation: I touched U1 STM body to check for overheating, and the D1 LED blinked rapidly, while 1kHz square wave remained good.

I bought from a seller who does not provide warranty. Please advice how I can troubleshoot the board.

Thank you.

[jye1]

Please check the soldering of LCD. If it looks good please contact JYE Tech at jyetech@163.com.

[Chee]

Hi, the LCD solder contact was rechecked multiple times but still white screen. So I returned the unit for a refund and bought a second unit from different seller. The second unit came with proper dso shell packing box and is operating well. Thanks.