If you connect the power lines and a contrast control (or strap it to maximum contrast), you can adjust the contrast control to see some blocks on one line of the display. It doesn't prove a great deal, but it shows it's not totally dead.danae_fiz said:how can i test a 16X2 LCD? do i just connect the Vss and Vdd to source to see if it's working or not? please help. if there's 2 pins with +Vled and -Vled how to connect it so that the back panel light for the LCD is on??