I just updated my Centos7 Pi3 "yum update" on 5/18/2018, and now I am facing a rainbow screen. Red pwr light is nice and strong, even changed power supplies. Green ACK light blinks 2 times and stays off. Screen is stuck on the rainbow - no activity, nothing, with or without the USB drive, nothing. USB drive does not power up either - nothing. Tried pressing the keys 1 to 4 at power up, then any key on multiple pwr ups, no effect. Found a similar post on https://www.raspberrypi.org/forums, search "raspberry pi3 stuck on rainbow screen after Jessie update". Removed micro card and read files on another machine Without listing all the files individually, kernel7.img, the dtb files bcm2708-rpi-xxx.dtb, bcm2710-rpi-xxx.dtb, bcm2835-rpi-xxx.dtb, bcm2836-rpi-xxx.dtb, gcm2837-rpi-xxx.dtb. All are dated 5/18/2018, the day of my yum update. The kernel is kernel-4.14.27-v7.1.e7.img dated 3/19/2018. Other files bookcode.bin, fixup*.*, LICENCE.broadcom, start*.elf, COPYING.linux all date 3/16/2018. A file initrd-plymouth.img dates 2/26/2018. I also see what look like older kernel files: kernel-4.9.75-v7.1.el7.img - 1/9/2018; kernel-4.9.70-v7.1.el7.img - 12/19/2017; kernel-4.9.64-v7.1.el7.img - 11/24/2017; kernel-4.4.26-v7.1.el7.img - 10/22/2016. Any ideas on how to downgrade to previous kernel or how to fix this? Can't get into single user mode - pressing keys on pwr up has no effect. I don't know enough about the kernel and the boot process to start messing with them. I am stuck. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/arm-dev/attachments/20180519/f15654ef/attachment-0005.html>