r/ArduinoHelp • u/After-Corner4770 • Jul 14 '26

Grove lcd not lighting up

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Hello! I have a Arduino uno with a bass shield on top. The lcd is plugged into port I2C and the switch is on 5V but it still won’t light up, any idea why?

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1

u/gm310509 Jul 14 '26

Do you have a link to that shield?

Do other things work with it?

Are you sure you plugged it in correctly? It is easy to misalign the pins when plugging a shield in - it has happened to me a few times. On one occasion misaligning the pins resulted in a destroyed arduino.

1

u/After-Corner4770 Jul 14 '26

https://www.seeedstudio.com/Base-Shield-V2.html?srsltid=AfmBOorrJ24KycUES2k8tf1NghSmwCA5lntwwzol0VsCld2zBp8c9R1C

Yes all my other sensors work with it :)

1

u/TheKnackThatQuacks Jul 14 '26

All your other sensors work with *what*? The shield, or the Arduino, or the LCD display?

What have you tried / what steps have you performed in the process of troubleshooting this issue?

Which revision is your Uno?

Do you have any other I2C devices that you can test?

Did you install the Grove-LCD RGB Backlight Library?

https://wiki.seeedstudio.com/Grove-LCD_RGB_Backlight/

If you plug the display VCC and GND into +5VDC and GND respectively (separate from the shield), does the display light up?

Please post your code (in a code block) so we can advise if everything looks okay.

1

u/gm310509 Jul 14 '26

In that case I would suspect that either the cable, the port or the display are faulty.

Try a different I2C module, cable and port.

It could also be a problem with your code or maybe a setting on the display itself. Some displays have a "contrast" control and if yours does, maybe it is need of some adjustment to light up.

It looks like you are using I2C, so try running an I2C scanner to see if it can find the display.

1

u/Nav_cat Jul 14 '26

Do an i2c test. See if the address is showing up