Raspi 5 not booting, 4 green blinks, no video

when i first booted my SD card that used to work on my rpi3 it got stuck at uboot, a little reading later i decided to just make the recommended SD with rpi-imager black screen only, 4 pulses (the last one is a bit clipped so maybe its 3+1 short?) booting without a card has the same behavior, nothing is shown on screen (not even the diag stuff?) i overwrote the sdcard that got stuck at uboot but i am at least 90% certain that my (only) microhdmi to hdmi cable didn't break any next steps? i couldn't find the blinking patterns for rpi5

the pi 3 os wont work, but update your imager. go into os and press "erase"

after that try again using https://discord.com/channels/818384379197784084/1193923435789824050 just to get rid of any problems before we properly troubleshoot