Slint: No Sound, Screen not in text mode

[Linux for blind general discussion]

I have installed the latest slint onto a hard drive, choosing
"start in graphical mode"
. Speech was available during install. However, I rebooted with my braille display attached, saw that ubiquitous
screen not in text mode
message, and there is no sound.
I attempted to get a console with ctrl+alt+f1-2-3. No console prompt appeared. Obviously it has started up, because the
screen not in text mode
would not be there otherwise.
During install, I chose the mate desktop, but I forget which window manager I chose.
Any tips for rescuing this situation would be appreciated.
Rob