Raspberry Pi won’t boot after updates

12th February 2020

Error on screen looks like this

[ 0.530840] bcm2835-clk fe101000.cprman: plla: couldn’t lock PLL
[ 0.631843] bcm2835-clk fe101000.cprman: plla: couldn’t lock PLL
[ 0.735166] bcm2835-clk fe101000.cprman: plla: couldn’t lock PLL
[ 0.835890] bcm2835-clk fe101000.cprman: plla: couldn’t lock PLL

Don’t format just yet

replace 2 files on the SD card fixup4.elf and fixup4.dat as described here https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=262649&start=75#p1610152

Make sure you have expanded the file system on the SD card.
ssh into pi, usually logon pi pw raspbian
sudo raspi-config
advanced
expand file system
reboot