I encountered the same or a similar issue. Powered up normally. Initial setup asked to upgrade software, the system including touch screen got stuck during the upgrade. After waiting for some hours I unplugged the device, plugged it back in and the screen stayed black. I was able to finish the upgrade via SSH, but this did not help.
dmesg repeatedly logs the following (approx 500 ms between repeated entries):
[ xxxx.xxxxxx] hdmi-audio-codec hdmi-audio-codec.16030.auto: ASoC: error at snd_soc_component_set_jack on hdmi-audio-codec.16032.auto: -95
[ 3112.805324] vc4-drm gpu: bound fe400000.hvs (ops vc4_hvs_ops [vc4])
[ 3112.805982] Registered IR keymap rc-cec
[ 3112.806332] rc rc0: vc4 as /devices/platform/soc/fef00700.hdmi/rc/rc0
[ 3112.806435] input: vc4 as /devices/platform/soc/fef00700.hdmi/rc/rc0/input16033
[ 3112.812424] vc4-drm gpu: bound fef00700.hdmi (ops vc4_hdmi_ops [vc4])
[ 3112.819476] Registered IR keymap rc-cec
[ 3112.819574] rc rc1: vc4 as /devices/platform/soc/fef05700.hdmi/rc/rc1
[ 3112.819672] input: vc4 as /devices/platform/soc/fef05700.hdmi/rc/rc1/input16034
[ 3112.825904] vc4-drm gpu: bound fef05700.hdmi (ops vc4_hdmi_ops [vc4])
[ 3112.946899] hdmi-audio-codec hdmi-audio-codec.16033.auto: ASoC: error at snd_soc_component_set_jack on hdmi-audio-codec.16033.auto: -95
[ 3113.057284] hdmi-audio-codec hdmi-audio-codec.16032.auto: ASoC: error at snd_soc_component_set_jack on hdmi-audio-codec.16032.auto: -95
[ xxxx.xxxxxx] vc4-drm gpu: bound fe400000.hvs (ops vc4_hvs_ops [vc4])
I have now flashed the eMMC with Ubuntu Desktop 21.04, and also the current Raspberry Pi OS - in both cases the screen never goes online.
Is it possible that some module ha to be enable to make the screen work?