Maybe I'm guilty of extrapolating from my behaviour of one Pi4. I got it around 2020 and its "uname -a" gives:That is odd as I have never edited /boot/config.txt on any Pi4 (or Pi3) and they all boot fine without any HDMI monitor attached.
Might just have been your single Pi4 that exhibited that behaviour?
Linux martin-pi4 5.4.83-v7l+ #1379 SMP Mon Dec 14 13:11:54 GMT 2020 armv7l GNU/Linux
I've never updated it to a more recent kernel because I had a problem with an update "killing" TVHeadend so I reverted to an older disk image that I had downloaded - it may date from when I first bought the Pi. It was one of those situations where a working Pi was higher prioirty than troubleshooting the cause. (Spot the well-known bug in the 'date' command's output in uname: putting the year (2020) after the timezone (GMT) instead of after the day number (14) or the month name (in UK format) - something I routinely fix on all Unix installations by tweaking the en_GB locale.)
I also found that I had to put in the lines that forced 1920x1080 without a monitor, otherwise RealVNC produced a window that was about 200x100 and was all black. Maybe there were a few hardware/firmware problems in the early days.
The other one related to an external HDD that was powered by a powered USB hub (to avoid overloading the RasPi PSU). The same disk and hub worked fine on my Pi 3 but would hang the Pi4 if the hub and Pi were both turned on simultaneously (eg after a power cut); power-cycling the hub once this happened allowed booting to continue. I now use a powered caddy and a SATA drive rather than a powered hub and a USB drive. Connecting the Pi to the hub by a lead that had the +5V line cut didn't help: someone on this forum suggested trying this because the Pi 4 allegedly didn't like booting if power was being fed "upstream" from the hub to the Pi via the USB cable. That one was 100% failure with the old topology and 100% fixed with the new one. It happened before any GRUB messages appeared on the screen, so no error message to be able to google
Statistics: Posted by martinu — Sun Sep 01, 2024 8:19 pm