HDMI audio and monitor stop working after update

Question

This is my dual monitor setup:

Ubuntu 16.04 xenial

x86_64 Linux 4.4.0-157-generic

GeForce GTX 750 Ti

Asus Z170-A

Everything was working fine, then, after some update that I can't pinpoint my HDMI monitor stopped working giving a blank screen.

After changing the screen resolution from 1680x1050 to 1600x1000 the image came back. I now have no HDMI audio (it disappeared from the Sound Settings) and am unable to change the resolution back to 1680x1050 as this causes the screen to go blank and have to revert to the previous configuration.

Previously, the login screen appeared on both screens, now it only shows on the DVI monitor.

I am currently using NVIDIA binary driver 384.130.

I've purged and installed several different NVIDIA drivers from ppa:graphics-drivers/ppa to no avail, some of them actually cause the system to boot to a blank screen with a blinking cursor. I've purged everything and went back to the distro proprietary tested one.

The cable and monitor work perfectly (video and audio) on another computer.

If I try to boot from a live 18.04 USB drive the boot fails and only shows a blank screen without the blinking cursor.

I paid no attention to the packages that were being updated since every update has worked flawlessly for years, but something broke this time.

Any help would be appreciated.

Screen 0: minimum 8 x 8, current 2880 x 1154, maximum 16384 x 16384
DVI-I-0 connected primary 1280x1024+1600+130 (normal left inverted right x axis y axis) 376mm x 301mm
   1280x1024     60.02*+  75.02  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   640x480       75.00    59.94  
DVI-I-1 disconnected (normal left inverted right x axis y axis)
DP-0 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected 1600x1000+0+0 (normal left inverted right x axis y axis) 470mm x 300mm
   1680x1050     59.95 +
   1920x1080     59.94    50.00    60.05    50.04  
   1600x1000     60.00* 
   1440x900      59.89  
   1280x1024     75.02    60.02  
   1280x960      60.00  
   1280x720      59.94    50.00  
   1152x720      60.00  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x480       59.94  
   640x480       75.00    59.94    59.93  
DP-1 disconnected (normal left inverted right x axis y axis)

More info as requested:

nvidia-415
nvidia-430
nvidia-418
nvidia-410
nvidia-384
nvidia-340

lshw:

  *-display               
       description: VGA compatible controller
       product: GM107 [GeForce GTX 750 Ti]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a2
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
       configuration: driver=nvidia latency=0
       resources: irq:135 memory:de000000-deffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:e000(size=128) memory:df000000-df07ffff
  *-display
       description: Display controller
       product: HD Graphics 530
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 06
       width: 64 bits
       clock: 33MHz
       capabilities: pciexpress msi pm bus_master cap_list
       configuration: driver=i915_bpo latency=0
       resources: irq:132 memory:dd000000-ddffffff memory:b0000000-bfffffff ioport:f000(size=64)