yet another blank screen(s) post

[wmldwilly]

Laptop: Asus N550, the 16" internal touchscreen equipped model with all USB3.0 ports and dual graphics (intel and NVidia)

Complete success with Windows 8.0: using SIIG branded and Iogear branded usb-dvi and usb-vga adapters, for 1, 2, or even 3 external ELO 1739L touchscreens and/or multiple ELO 1900L DVI touchscreens, or mixtures of both.

Update to Windows 8.1 *before* updating displaylink drivers to 7.4.

complete failure - same as many other forum posters, external screens are available to the OS, but only display a black image. I additionally know the monitors are functioning because the touch surfaces are all recognized and inputting as expected. extended desktop of the full compliment of monitors is even viewable with VNC clients, but the displaylink USB adapters themselves produce "no video input" to the monitors - the backlights illuminate a black raster.

Upon the RAREST occasion when switching from MIRRORED to extended desktops, the external displays hosted by displaylink adapters will momentarily come to life and show the cursor, then return to black again.

I've followed the uninstall/reinstall/run cleaner/verify the PID is not 8060 or whatever the undesireable number is square dance ad nauseam for hours and hours, and have been unable to produce successful operation of the displaylink adapters. Moving all of the displaylink adapters to any given windows7 machine I have running shows that they function perfectly.

This issue happened and never went away upon the very first restart from installing windows 8.1. All pertinent updates have been applied up to today (dec. 1) and the problem remains.

output from the displaylink debug tool is attached.

You cats have an 8.1 problem, and 7.4m2 and all the hocus pocus uninstall/reinstall dances aren't getting it worked out.