Did both of those suggestions already, the quick access software before I realized the problem was occurring even before Windows, so quick access does nothing for the function keys or any other keys as it runs under Windows. As for the cable itself, a little back story on the laptop. It was brought into my shop because the LEDs would light up, keyboard would light up, but no display, not even via HDMI to another monitor. I tried the little "hidden" battery reset button, didn't do anything, so with a big sigh (just because I've been having to disassemble soooo many different laptops lately, mostly Dells) I took the bottom shell off, removed batteries and RAM, put them back, turned it on again, same thing, no display. Removed the RAM put in some other RAM that I had laying around, turned it on, and the display worked! Took that RAM out, put his RAM back in, turned it on, and it worked!! Proceeded to boot into Windows, discovered the keyboard wasn't working. Shut it down, reseated the keyboard cable several times, tried again, this time hitting F2, F1, Esc, Del, F12 keys that usually have some sort of initial function on startup (system has a SSD and boots fast, so I just initially marked the no function response up to that). Still no keyboard function in Windows. Browsed over to device manager, keyboard PS/2 is listed as having no problems, functioning correctly, as are all the devices. Hooked up USB keyboard and watched the second keyboard show up in device manager. *EDIT: Ran mdsched (widnows memory diagnostic), it passed with flying colors.* Proceeded to Acer website to download and install the latest BIOS, touchpad driver (Elan, not Synaptics), chipset, graphics, audio, quick access, basically everything. Tried to get into BIOS after every reboot. Did the BIOS update last which forced the system into the BIOS setup, at which time I learned the keyboard wasn't even working at that level. Sighed again, took the laptop completely apart. Looked at the back of the keyboard, that cable is connected in there very well, covered, protected, it's not just going to wiggle loose out of there, same with how the cable connects to the motherboard, once it's seated in there and clamped down, it's not coming loose. Plus I observed that the keyboard itself isn't going to be easily replaced as it's plastic soldered/riveted to the top palmrest panel. Sigh again, put it back together, boot it back up, freak out again this time because there's no sound, reinstall sound driver then /facepalm. Take the bottom cover off again and plug in the speaker wire (*slaps self*) Puts it all back together, proceeds to do research online, and return the laptop to the customer with a USB keyboard and the assurance that I will look further into the keyboard problem. Good laptop otherwise, 6th Gen i7, 16GB RAM, SSD primary, and one additional thing that I should add, but I don't know why it would make a difference, the laptop owner modified the DVD drive bay to house a secondary 1TB HDD, which was functioning just fine. Towards the end of working on it is when I got really perplexed, that the power button is one of the many keys on the keyboard itself, connected to the motherboard by the same cable, it works but absolutely none of the other keys on that keyboard do, there's no separate cable to the motherboard from the power button, it's part of the main keyboard cable >.<

Oh yeah, on the BIOS settings. I forgot to mention, I had to force the laptop into the Windows repair options by dropping power on it during it's boot cycle about 3 times, then choose the repair option to change UEFI settings or whatever, which forces the system to reboot into the BIOS settings. Looked closely through all the settings, there's only about 2 that can actually be changed ... VERY limited BIOS... Only one having to do with input was regarding the touchpad, basic or advanced (something having to do with the I2C driver), tired both settings, and even tried uninstalling the I2C driver in device manager, which only caused the touchpad to stop working, it reinstalled itself on reboot, but keyboard still not working, and makes me ask myself, faulty I2C? I don't have a schematic, but it seems like that's what the keyboard might be running through

tried both settings

If the keys don't even work in the BIOS settings, ie. navigating the BIOS settings, how are Windows drivers going to help? I've had to use a USB keyboard to navigate through the BIOS settings, but yeah, regardless, I got all the applicable drivers from the Acer website, I'm not using some third party driverbooster malware garbage

The only key on the keyboard that works is the power button key, upper right most key, on the keyboard, turns the laptop on/off