The LCD only works in a very narrow range about 60Hz. If the
signal is outside, it does not show anything.
Workaround: external Monitor or text installer
There are always going to be cases where the GUI installer is not
going to work, which is why we provided the fallback of text mode. We
are working to improve the number of cases in which the GUI installer
will run and will look at the ThinkPads at the next release.