# Arduino UNO Lcd display not working **URL:** \ **Category:** Displays\ **Created:** [January 18, 2026, 4:39am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868 "2026-01-18T04:39:00Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![nexavoid](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/nexavoid/32/1132299_2.png) [@nexavoid](https://forum.arduino.cc/u/nexavoid)\ **Post date:** [January 18, 2026, 4:39am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/1 "2026-01-18T04:39:00Z")
Actually I am doing a project smart parking system I need lcd for it.iam using Arduino UNO Lcd 16×2.address 27 verified.Lcd display is showing these boxes iam trying since 1 day I have installed hd44780 and liquid crystal i2c libraries I also checked and rotated potentiometer to the max contrast but it's showing text ![17687110802836099128506704158507](https://europe1.discourse-cdn.com/arduino/original/4X/0/c/1/0c172530bd1e81de28ac7fafc1018b8477d20153.jpeg) ![17687111135302856054864701792380](https://europe1.discourse-cdn.com/arduino/original/4X/6/6/c/66c0f3822358840e08949383faca4c763305537e.jpeg) ![17687109867604082642392709138351](https://europe1.discourse-cdn.com/arduino/original/4X/3/c/6/3c6724dd7a01587b1fdf18569bb2dccb0ec9830b.jpeg) ---
**Author:** ![van\_der\_decken](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/van_der_decken/32/1006976_2.png) [@van\_der\_decken](https://forum.arduino.cc/u/van_der_decken)\ **Post date:** [January 18, 2026, 4:49am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/2 "2026-01-18T04:49:57Z")
![image](https://europe1.discourse-cdn.com/arduino/original/4X/0/f/7/0f7c62500e843d4b0e33fc9a5f26755f61897a83.png) No. Just no. ---
**Author:** ![time\_document\_3108](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/time_document_3108/32/1245996_2.png) [@time\_document\_3108](https://forum.arduino.cc/u/time_document_3108)\ **Post date:** [January 18, 2026, 4:50am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/3 "2026-01-18T04:50:03Z")
try 0x27 instead of 0\*27 you may also need a `Wire.begin();` before lcd.init() ---
**Author:** ![LarryD](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/larryd/32/215550_2.png) [@LarryD](https://forum.arduino.cc/u/LarryD)\ **Post date:** [January 18, 2026, 5:05am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/4 "2026-01-18T05:05:28Z")
- And fix this: ![IMG_4385](https://europe1.discourse-cdn.com/arduino/original/4X/e/5/b/e5b40cf937ac56af4d0c416036500cfaf5922ec9.jpeg) ---
**Author:** ![nexavoid](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/nexavoid/32/1132299_2.png) [@nexavoid](https://forum.arduino.cc/u/nexavoid)\ **Post date:** [January 18, 2026, 5:16am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/5 "2026-01-18T05:16:54Z")
Thank you so much ![17687132527253126574514955399139](https://europe1.discourse-cdn.com/arduino/original/4X/5/8/1/581fa2816aafc0024e8a0f74d61b4092782bd208.jpeg)but the text is not clear even if i rotate the potentiometer ---
**Author:** ![time\_document\_3108](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/time_document_3108/32/1245996_2.png) [@time\_document\_3108](https://forum.arduino.cc/u/time_document_3108)\ **Post date:** [January 18, 2026, 5:21am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/6 "2026-01-18T05:21:41Z")
try a adjusting contrast to a lower value. alternately you can try to wiggle the wires looking for bad connections. ---
**Author:** ![van\_der\_decken](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/van_der_decken/32/1006976_2.png) [@van\_der\_decken](https://forum.arduino.cc/u/van_der_decken)\ **Post date:** [January 18, 2026, 5:26am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/7 "2026-01-18T05:26:00Z")
> [@nexavoid](#): > > the text is not clear even if i rotate the potentiometer ![image](https://europe1.discourse-cdn.com/arduino/original/4X/6/2/b/62bf0a23218536c61dcc8766f0592b64627278fb.jpeg) Without the backlight jumper installed, I'm not at all surprised. ---
**Author:** ![nexavoid](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/nexavoid/32/1132299_2.png) [@nexavoid](https://forum.arduino.cc/u/nexavoid)\ **Post date:** [January 18, 2026, 5:28am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/8 "2026-01-18T05:28:12Z")
Backlight jumper?? Could you please explain how to do it ---
**Author:** ![time\_document\_3108](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/time_document_3108/32/1245996_2.png) [@time\_document\_3108](https://forum.arduino.cc/u/time_document_3108)\ **Post date:** [January 18, 2026, 5:28am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/9 "2026-01-18T05:28:26Z")
Van Der Decken, you have a keen eye, that's for sure! ---
**Author:** ![time\_document\_3108](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/time_document_3108/32/1245996_2.png) [@time\_document\_3108](https://forum.arduino.cc/u/time_document_3108)\ **Post date:** [January 18, 2026, 5:36am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/10 "2026-01-18T05:36:22Z")
![image](https://europe1.discourse-cdn.com/arduino/original/4X/a/6/7/a67eaa08d6adaf0324ba6e9197fc26631f8115e2.jpeg) ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [July 17, 2026, 5:50am UTC](https://forum.arduino.cc/t/arduino-uno-lcd-display-not-working/1425868/12 "2026-07-17T05:50:16Z")
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