>and I tried powering on with the eMMC switched off and then switching it back on when the LED comes on,
>which also did not resolve anything.
If you did this with a SD card inserted, this strongly suggests that the SD card is bad,
unless you switched really quick (try leaving 5 seconds)
Use the mrfixit distro, connect to wifi, mrfixit_update.sh (for your SD)
Since you have vt's (virtual terminals) , it is booted (you have 5, F2-F6)
I had a large update fail, due to sleep, tiny, almost invisible letters in vt2,, setfont -d,, (double, still faint),
no wifi, sudo ifconfig, yep no wifi, nmcli didn't work but nmtui did,, then pacmac failed,
a lock file I couldn't find,,, start<tab,tab>,, none worked,, su, startxfce4 worked, finished update
rebooted OK
You know, "usb to sd card adapter" even in amazon are not that expensive,,<10-$20,,, usb2 ones are 1/2 that
--edit--
One other thing you can try is a hard reset,, hold pwr button 20+ seconds (for SD boot problem)
--more--
I should explain this,, some (>1,<5) people with manjaro have had SD problems
My guess is uboot internal generic dtb has phase set wrong
So, if SD is good (too bad you can't test with h2testw, bad cards are NOT uncommon)) and you get no boot with emmc off
then with emmc off, SD inserted, do long press, then start press, maybe it will boot
To your original problem, no x (since you have vt's it is booted) check,,, sudo systemctl status sddm ,, maybe stop , start, status
x is on vt1, not the usual vt7
>which also did not resolve anything.
If you did this with a SD card inserted, this strongly suggests that the SD card is bad,
unless you switched really quick (try leaving 5 seconds)
Use the mrfixit distro, connect to wifi, mrfixit_update.sh (for your SD)
Since you have vt's (virtual terminals) , it is booted (you have 5, F2-F6)
I had a large update fail, due to sleep, tiny, almost invisible letters in vt2,, setfont -d,, (double, still faint),
no wifi, sudo ifconfig, yep no wifi, nmcli didn't work but nmtui did,, then pacmac failed,
a lock file I couldn't find,,, start<tab,tab>,, none worked,, su, startxfce4 worked, finished update
rebooted OK
You know, "usb to sd card adapter" even in amazon are not that expensive,,<10-$20,,, usb2 ones are 1/2 that
--edit--
One other thing you can try is a hard reset,, hold pwr button 20+ seconds (for SD boot problem)
--more--
I should explain this,, some (>1,<5) people with manjaro have had SD problems
My guess is uboot internal generic dtb has phase set wrong
So, if SD is good (too bad you can't test with h2testw, bad cards are NOT uncommon)) and you get no boot with emmc off
then with emmc off, SD inserted, do long press, then start press, maybe it will boot
To your original problem, no x (since you have vt's it is booted) check,,, sudo systemctl status sddm ,, maybe stop , start, status
x is on vt1, not the usual vt7