Waveshare 3.5c screen not working after Raspberry Pi 4 firmware upgrade

[rhannink]

Hallo,

I performed a
sudo apt full-upgrade
update on the latest Buster RC2 image, to be sure I got the latest firmware (EEPROM) for the Raspberry Pi 4.
After this upgrade the Waveshare 3.5c was not working anymore. But when I choose PiScreen 3.5 (v2) I get the UI again? I saw that al sorts of overlay files were updated. Is this a known Problem? How can I solve this?

Kind regards,

Remco Hannink

[MrBroccoli]

My waveshare didn’t work when I moved it and the SD card from pi3 to pi4. It did work when I moved it back. No idea why, but when I bought pi 4 case with a similar screen, it wasnt an actual waveshare.

[MrBroccoli]

My current zynthian daydream

Not off to a great start. Swapped in the SD card, the soundcard, and the screen from pi3… And instantly had a one of them “oh no, please no” moments. Blooming screen don’t work on pi4. I thought I had blown another one, but no… Swapped it all back to pi 3 and it was all fine… What could be wrong I wonder? As I’m trying to find out, a huge bee flies into my shed and bounces off all the lights. Luckily I had the pi 4 box handy and used it to help the bee back outside again.

See here

[wyleu]

So it’s screens and Pi4’s that’s the problem…?

Presumably this might be why there are so many cheap screens out there …

[rhannink]

Everything worked fine on the Raspberry Pi 4 (clean new Install of RC2 image), until I upgraded to the latest RP4 firmware. During this proces also a lot off overlay files were upgraded. After this upgrade the Waveshare 3.5c screen did not work anymore.

The screen is an ordinaal Waveshare product.

[Baggypants]

Maybe see if you can get it working with Raspberry Pi OS and figure out what the difference is?

[wyleu]

That’s the way I got the 3.5" working initially.