Booting from 18.04 Live USB, only ever get to wallpaper - no cursor, no desktop, no choice of Try or Install.
AMD A4-5300 with Radeon HD 7480D on PCI Express. BIOS is set to use PCI instead of onboard graphics.
16.04 is installed on hard disk and works fine.
USB boots fine in another PC.
Found the answer.
Despite that I set my BIOS to use the PCI graphic card, Ubuntu still finds the MB display adapter, and uses that. When I attached a second monitor to the MB display adapter, I could see the Live CD Try or Install option.
Is there a way to interrupt the Live CD grub boot, and specify a display adapter to use?