l> have to literally fiddle with video port on computer while
l> repeatedly restarting w/power button before it finally works.

Not good for the system having to do that and presumably once you get
it working it's OK apart from the browsers ? Usually I've found the
root cause of reluctant booting is hardware - number one suspect being
the power supply unit and I'm still coming across these with blown
capacitors though this scourge appears to have gone on motherboards !!

Are you able to fit a replacement power unit, even temporarily to
check that this fixes the reluctant boot ?