I was testing out whether my 16x2 LCD works. I hooked it up to the arduino.

Some white box appeared which probably meant it works fine, but the box and the blue background looked very dim even when the potentiometer was turned to the maximum, and did not have the bright blue background which I saw on google.

FYI I soldered copper wire on the LCD and shoved them onto the breadboard since I did not have any pin headers. Would this be a cause of the problem?


One from google

  • Looks like you have no back light. Is the back light wired correctly?
    – Majenko
    Jun 18, 2019 at 9:17
  • I can't see much solder on the LCD on that photo. Are all of those wires soldered on?
    – Nick Gammon
    Jun 18, 2019 at 10:52

1 Answer 1


I suggest you invest a dollar or so and get some proper wires. Those bare wires, which don't look soldered on, from the top view, just don't cut it. It also looks like the individual wires would short with each other (or are actually shorting).

It will light up when the backlight is correctly connected, which is impossible to tell from your photo.

  • It even looks like the “K” pin does not have a wire on it at all. Just a blob of solder filling the pad. Jun 18, 2019 at 11:26

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