OS: Debian Testing / dual boot with Windows 10
Windows resolution is 3840 x 2160.
RAM: 16 GB. HDD: 1 Tb.
Debian "Testing" was installed for me at an Install Fest earlier this year. The person who installed it felt that my machine was capable of running "Testing" without any problems ....until this morning.
PROBLEM? Machine hangs once booting from the Boot Manager. UNABLE to read the messages, since during the boot session the text is extremely TINY. So tiny, that even with a magnifying glass is no help.

Once booted to the login (desktop) the text is more normal in size. BUT I cant boot into Debian because of the system hanging!
This is being posted from the Windows 10 partition.
What do I do?
TIA for any assistance...