20x4 I2C LCD Not Working Anymore

Using Arduino Displays
1

Hello.

I have a custom pcb with an Atmega2560 and an 20x4 I2C LCD with the I2C backpack from JOY.IT.

I use an onboard 5V regulator (TSR_1-2450) that converts the 12V to 5V that powers the pcb and LCD.

Everything was working fine for hours, I use the LCD to interface with the user with an encoder and menus.

Then I moved the system to a tractor (with the same 12V power) but the 12V socket sometimes disconnects and connects rapidly, and now the LCD ligths up but doesn't show text.

I have not changed the code, I have already tested the I2C scanner code, but no device is found.

If I connect a new LCD everything works.

This has happened to me in the past, is it possible that the LCD is burned now?

And if yes, why does this happens?

2

In answer to the first - Obviously.
In answer to the second - Being in a tractor, it's not unlike an automotive environment, many hazards there (electrical and mechanical).

3

An auto motive environment has no stable 12v voltage. 14.5 an spikes of over 30v are possible.

4

I understand. But it is a tractor with 3 years, with lot's of other electronics that doesn't burn.

And it is strange that the lcd burned but the atmega2560 don't.

5

I understand. But the 5V regulator can go up to 36V of input voltage.

And the atmega2560 didn't burned. If there was a voltage spike, everything else should have burned.

6

Good Vibrations!

But maybe not for this kind of display.

7
8

Did you checked the contrast potentiometer on the backpack of display? I had the same issue and it was the potentiometer with had a bad contact.

9

This hapenned with the system on a table.

The tractor was just proveding the 12V.

10

Yes.

I wrote on the first topic that the system has worked for hours before this happened.

11

I Feel Moved! But can't tell, as Not Working Anymore.

12

LCD displays quit very slowly due to age or due to sunlight heating the crystals. Your problem happened too suddenly for either to have happened. Look for cold solder joints.

13

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