Display issues with Elitebook 840 G3

[falconer80]

So I've verified that there are a number of odd issues with the Elitebook 840 G3 and its configurations with various monitors already in this support forum. 

I currently have the following setup:

 - HP Ultraslim Dock

 - HP Elitebook 840 G3 (updated on all firmware/drivers/bios/etc as of 8/17/2017)

 - HP Z24NQ (1440P)

 - HP Z24NF (1080P)

 - Laptop opened and running its 1080P monitor also

I've been working with the setup for a week, in the 3 monitor setup.  It appears that there is something wrong/odd about the Z24NQ.

The NQ will randomly go dark/black and stay off until I hard power the display off and restart the monitor.  This appears to be a common issue with the 840 G3's in other posts I've researched.  Other monitors seem to have the issue, but the Z24NQ is repeatedly having this issue, almost a week or so into its use with my laptop/docking station setup.  

I would like to know if anyone else is having the issue, or if HP support can reach out to me and see whats happening?  I believe there is some kind of incompatibility between a driver or firmware (laptop/dock) and the monitor itself.  This is completely repeatable and I can showcase pictures.   

When the issue occurs the following happens on the NQ monitor:

- Monitor goes complete black.

- Power indicator stays on (solid white) at no point does it goto sleep.

- Laptop thinks the monitor is still present, and displaying.

- Monitor does not appear to register a sleep cycle at all, even after turn on/turn off.

- Extended period of cooldown seems required to regain functionality, turning it off for 5+ minutes seems to restore functionality.

- Sometimes when immediately turned off/on the NQ will display the desktop and then immediately drop to black screen again.    This is unpredictable though and happens infrequently.

I've tried several combinations of monitors with this laptop and no problems with this:

- Z23 no issues

- Z24NF no issues

- Z24N no issues

All other HP monitors seem to be completely fine without any concerns. I've also had others try their dell monitors, which again experience no issues at all.   So this seems to be a model specific bug.  It is repeatable on all the NQ monitors I've tried. 

Any help/input would be GREATLY appreciated HP!

[Gary_Rowe]

How are your monitors connected? Are they connected via DP or are the connected to the VGA port and a DP?