Hyperpixel 4.0 inch square touch not working

Hi,

I have a Hyperpixel 4 inch square display that I would like to start using again. It’s been in a closet for a couple of years. I only get a weird blotch and no image. How to debug this?

I did:

  • grab a Pi 3B & 8GB sd card;
  • installed a fresh Raspberry Pi OS with desktop (old fashioned, with dd);
  • tried this first with a regular monitor, mouse and keyboard - this worked.

I added:

  • dtoverlay=vc4-kms-dpi-hyperpixel4 to /boot/firmware/config.txt;
  • enabeld I2C;
  • a reboot.

No image. HDMI still works. Should I disable that?

The display shows this weird blotch:

Nothing stands out in dmesg or the logs.

Thanks!
Ferenc

You will need to have I2C disabled (sudo raspi-config nonint do_i2c 1 ) along with any other interfaces that use the GPIO.

I disabled I2C but still the weird blotch in the middle.

It slowly appears when I apply power to the Pi.

I wiggled the GPIO header (where the hyperpixel connects to the Pi) somewhat and now I have moving, colored lines. Progress!

IMG_4770