I also had Lubuntu groovy daily [20200708.1] boot on
lenovo thinkpad sl510 (c2d-t6570, 2gb ram, i915) lenovo thinkpad x201 (i5-m520, 4gb, i915)
but it failed to boot on
hp dc7900 (c2d-e8400, 4gb, intel 4 series integrated i915)
(same reaction as hp dc7700; I see the LED flash then it quickly proceeds to boot the hdd-installed OS on selecting to boot USB device)
I also had Lubuntu groovy daily [20200708.1] boot on
lenovo thinkpad sl510 (c2d-t6570, 2gb ram, i915)
lenovo thinkpad x201 (i5-m520, 4gb, i915)
but it failed to boot on
hp dc7900 (c2d-e8400, 4gb, intel 4 series integrated i915)
(same reaction as hp dc7700; I see the LED flash then it quickly proceeds to boot the hdd-installed OS on selecting to boot USB device)