I am attempting to revive my roommate's old MacBook Pro, A1226, MA895LL, which has GeForce 8600M GT as its dedicated graphics (see https://everymac.com/systems/apple/macbook_pro/specs/macbook-pro-core-2-duo-2.2-15-santa-rosa-specs.html). After some difficulty with installation, I realized that to boot properly, I had to set nomodeset in grub, as indicated by this article: How do I set 'nomodeset' after I've already installed Ubuntu?
Things seem to work fine except for two major issues: the external monitor is not recognized (DVI, works with macOS) and the wireless (able to work on this). In attempting to get the monitor to work, I noticed that the nvidia driver 340.107 is available through proprietary drivers. Upon choosing this driver and restarting, the laptop successfully boots to grub, but then hangs on a terminal screen. I am able to go to a new terminal via ctrl alt F2, however the screen flickers back to tty1, preventing input into the tty2 (or tty3, etc.): https://makeagif.com/gif/macbook-error-V-e_yY
I am attempting to apply this fix (Ubuntu 18.10: Installing nvidia drivers leads to black screen after GRUB) however with the screen flickering like this, I am unable to login to make any changes. Note I have tried this both with nomodeset on before I restart, and alternatively with it off. However, as troubleshooting this issue requires completely reinstalling ubuntu each time as the flickering effectively bricks it, I'm not sure how to proceed.
--------EDIT 26 Feb 2019--------
I reformatted again and installed nvidia driver 340.107 before making any other system changes/updates and restarted to the same results. Stuck on the same boot up screen (after grub), trying a different terminal results in a flashing screen. So this leaves me with two questions: 1) what might be causing this, and how do I fix it? 2) Is there another method to get the external monitor recognized?
--------EDIT 27 Feb 2019--------
I reformatted yet again, this time uncommenting WaylandEnable=false as per my second link before restarting and was confronted with the same terminal that flashed. This being the case, I will ask a new question about getting an external monitor recognized and reference it here, as I am giving up on getting working nvidia drivers...