Corrupted 4" Waveshare ILI9486 display

Hi everyone,

I am really hoping someone has experienced something similar, and has a solution!

My 4" ILI9486 Waveshare (https://www.waveshare.com/4inch-tft-touch-shield.htm) is all of a sudden only showing a corrupted display of vertical lines. Some graphics are visible (I can see my clock updating etc). It has been working perfectly since early May. I’m really hoping I didn’t short something out.

I have tested it on 3 ESP8266 boards and a ESP32 board. Not code related as I have tried the TFT_ESPI tests, which load and display, albeit corrupted with the lines.

Hoping someone can help me diagnose this! I really don’t want to bin this excellent $30 display :frowning:

Hi cerevisis,

Did this occur the first time running the same code, or after a program upload?

The symptoms may look like an initialization issue with the controller.
Reducing the SPI bitrate may help.

I don't have this display, so I don't know. But the SPI kludge used on the board has a limitation on SPI speed to work reliably.

Thanks ZinggJm for the feedback. The lines appeared one day and got worse over a few hours. I have tried multiple test files, my code, old code etc. Nothing changes.

Using the TFT_ESPI library and I have tried lower the SPI bitrate but this didn't change anything. Maybe I should go lower. I will try tomorrow.

ZinggJM:
Hi cerevisis,

Did this occur the first time running the same code, or after a program upload?

The symptoms may look like an initialization issue with the controller.
Reducing the SPI bitrate may help.

I don't have this display, so I don't know. But the SPI kludge used on the board has a limitation on SPI speed to work reliably.

and got worse over a few hours

This would suggest a hardware issue.

My only remaining idea is to check the 3.3V after the LDO. Take a look at the schematics.