There is a fix about to be released but you have sign a legal document with Dell to get it before its released to the general public.
Contact your Pro support or Dell account manager if you can & sign an NDA.
Make sure the laptop is on the dock when you are doing the update. Also ensure you have the latest Bios and Display drivers.
It fixed my E7470.
It didn't solve my problem either. 4k still doesn't work at all, and with lower resolution external screens, the system is limited to two screens altogether. If I open the built-in screen when docked, then all three screens start flashing like crazy.
Saying that Dell's support is very disappointing would imply that there is any support to talk of. For $2000 other companies typically sell functional hardware. What makes Dell think that they don't have to?
This is slightly a different issue than the one originally posted.
The update has fixed all my colleagues flashing external monitors upon makeup / resume but I am now experiencing a 3-4 in a row monitor flashes on both external displays. The monitors both then settle.
Have you installed the display driver ending 4390?
I'm having the same "blackout" problems with my monitors when docked with my E7470 and Win10.
I'm current on the BIOS and display drivers, and when I tried to install Video_Firmware_FV9KP_WN32_3.10.1_A07 I get an error message:
Update result: 243
Error description: Product ID does not match, the firmware is for different board"
Is this not the right update/version to use?
(The page for the Synaptics VMM3320 MST HUB Firmware Update says:
Version: Version 3.10.1, A07
Release date: 21 Apr 2016
Last Updated: 21 Apr 2016
...but it seems that others have been successful in running it?)
And, yes, I tried running it while docked and on A/C.
Is there anyone from Dell that can help?
I tried this download on my E7470 and now my docking station is totally unusable - what was an intermittent second screen blinking issue after the machine coming back from power saving, it is now both two screens attached to my dock alternating from on and off.
A service engineer is now scheduled to come in to fix the problem. Dell needs to get on top of this issue - this is supposed to a high end business laptop for work.