Flashing PI Official 7in Touchscreen

[ceejayemm]

This problem relates (as reported to Raspberry Pi Organisation) to using the Official 7in Touch Screen with RPI 3B Plus and the latest RPiOS. However it seems the problem might be somewhere in the PI Firmware as I have been having the same problem with rAudio-1, possibly after updating via pacman -Syu. There seems to be some, as yet unsubstantiated, reports of this happening on early RPi 4b as well.

The issue is that after applying the update (where ever it comes from) and rebooting the RPi 3B, the attached screen continuously flashes and refuses to boot. I have seen this happening where the screen flashes as described but the rAudio-1 logo is alternately displayed (ie screen flash, logo, screen flash, logo etc etc). In my case the PI does eventually boot - after about half an hour, or more, of waiting. The issue and discussion around it is reported here:

raspberrypi/linux#4686

There isn't a fix as yet (Nov 24) but the workaround noted on this link does seem to work, at least for me. To get back to a working system you need to add:

dtparam=i2c_vc_baudrate=50000

to /boot/config.txt and reboot.

I hope this is use to anybody else who has this same setup as me.

Regards.

Chris