I’ve found the solution, I now know what goes and was not
the funny thing is, GeForce GFX 760 graphic is usable with proprietary driver under an up to date manjaro 64bit Computer system with intel graphic
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this combination is necessary, only with the geforce graphic does not work the boot process !
– in bios options, first init: onboard
– monitor signal wire connecting between (first) monitor and intel graphic connector (onboard graphic), an analog wire is enough
– a second signal wire connecting between (first monitor and nvidia graphic connector (dedicated graphic)
– monitor adjustment switch to the intel graphic connection (onboard graphic)
– boot with usb stick ect. the manjaro live system, default settings
– in either case, if both graphics, the intel and the nvidia graphic, has a signal connection to a monitor, all icons are not advisable; for installation it could be useful before boot to disconnect the signal wire from the nvidia graphic
– install the manjaro OS
– go to System Settings (giu), hardware configuration
— right mouse click on video-nvidia-47xx and install this driver (proprietary)
– ensure the signal connection between nvidia graphic and monitor (if before disconnect because of the icon issue)
– reboot the system
— the boot process, grub menue and so on, works only in the intel graphic world respectively shown there, til then the user application form will be show (user xyz and keyword)
---- if this is arrived, the intel graphic shows possible a loading symbol “manjaro” that is not more changing
---- this is the moment to switch on the monitor switch to the nvidia graphic wire
---- so the user can log on and KDE is starting
---- for control, wie can switch back on the monitor and see, the signal on the connecting wire from the intel graphic shows only black screen with above left a small line - this is now without funktion {so my solution , we need not an extra monitor} -
bumblebee or prime with changing the graphic mode back to intel or back, does not work in easy way;
– after install prime, indeed without usable funktion, I could still see with terminal command “inxi -G” the nvidia driver “nvidia v: 470.161.03”; after installation bumblebee (optimus swiching tool), there was only a N/A - this is because it makes for me no sense to take more workforce in it
other experience:
with linux suse Tumbleweed works also the boot process with this type of nvidia graphic card, but I had after installed nvidia driver (suse instruction) a slowly system. Things that need more cpu power was very slow. I think the cpu had to manage graphic work too;
I had found in the internet Forum (user with a little newer graphic model 9xx), an modification in a grub config file, what a graphic funktion from the nvidia card should shortly start at the boot process, but after than I could not more boot with nvidia graphic, I have all try, snapshot back, ne original config file and grub update, but only intel graphic could start after this try (all I mean is the bios switch, first init onboard or PCIe16)
I hope this is useful for other users 
if someone like to have screenshots or photos, please get in touch with me