OptiPlex 3040 micro, dual monitors using HDMI and DP ports, DP connection unreliable

This does not sound like a hardware failure. Did you check/test all of the Windows 10 power management options? Specifically the PCI Express- Link State Power Management setting? Or just set the Windows 10 power management to High performance and retest. Also, if the U2415s USB upstream cables are connected to the computer, be sure to disable the USB selective suspend setting.

Display issue here, too.

We have a monitor plugged into the HDMI, using an HDMI to standard video adapter and DP to DVI cable hooking the other monitor in.

If that is supposed to work, it does not.

What are the recommended hookup scenarios that are 100% supported by this 3040 Micro?

I am having issues with new 3040 Micro's as well with the display going black and never coming back.  Updated all drivers and BIOS.  Not a monitor or cable issue, works fine on other models.  I end up remotely rebooting and sometimes even that the display doesn't come back until 2-3 reboots.  I don't get a Dell logo when it starts up sometimes, so its happening before Windows is loaded.

I need to know the answer to this as well, Chris, and it would be particularly helpful to know that Dell does in fact intend that these computers support 2 monitors out of the box, and what the recommended cabling and settings are. I don't see ANY instructions available on this and since this is my first Dell that does not have a VGA connector to fall back on, this really has to work or I've got to return it. Hope to see an authoritative and conclusive post here.

[Edit:] I just looked up "Features and Design" of the Optiplex 3040 and here's something I found:

Small Form Factor Ports & Slots:
6.Natively supports 1 digital video output ( DP and HDMI ) | 7.Optional VGA

and Mini Tower Ports & Slots:
6.Natively supports 2 digital video outputs (DP and HDMI) | 7. Optional VGA

Am I reading this right? That the SFF is not in fact designed to support 2 video outputs? I'm not going to verbalize the comments that are going through my head, I just hope to get the correct answer here. 

Thanks.

Thanks.

I've been trying to get a small form factor to work with 2 displays innately (without a usb video adapter) for the past few days now and nothing I've tried has worked, I had a fellow tech tell me he got it to work but he has not been able to reproduce it.

I can't tell you how frustrating this has been, why on earth would any computer shipping in the year 2016 not support 2 monitors innately ?

"Am I reading this right? That the SFF is not in fact designed to support 2 video outputs? I'm not going to verbalize the comments that are going through my head, I just hope to get the correct answer here. "

I  Just registered my account to agree with you k9gardner.

If any Dell representatives would like to give us an official answer, it would be very much appreciated.

I've been looking closely at the Optiplex 3040 small form factor for a rollout we've got coming up, and we're very interested in the dual monitor capability.  I have not tested it yet, but the rep we're working with suggested using MST (multistreaming) capable monitors (like the U2415) to drive two monitors from a single DP port on the computer; that is a specifically supported configuration.

I like to know if it is possible to use 2 screens with the SFF model.

Turn off Display Port 1.2 on your monitor using the DisplayPort cable.

I can confirm that the SFF model supports 2 screens(when using a HDMI->DVI adapter and a DISPLAYPORT->DVI adapter . It was all working out of the box.

So the text on the site is wrong!

Small Form Factor Ports & Slots:

6.Natively supports 1 digital video output ( DP and HDMI ) | 7.Optional VGA

I am having this same issue with multiple (like 30+) Optiplex 3040 machines. Did you ever find a fix for it? We have spoken to Dell tech support multiple times and they are just as confused as we are. We have even tried to switch out the motherboard on about 30 machines to see if that fixes the issue and it has worked for a short period of time but the issue has returned on several computers. Some of the issues are on computers that are only using the display port and no HDMI, and some are using both.

What we have tried:

-switching monitors (to other brands as well as just other monitors same model)

-imaging (with our image)

-updating the drivers (video, monitor, and projector)

-updating the BIOS (some improvement after this but it does not completely fix the issue)

-switching cables

-converting back to VGA

-brought in an entire new setup from a lab and the problem still persisted

-updated the doc cam software

-Updated the Chipset

We've been working on this issue since August and have still not resolved the issue. Did you find a fix? We are now seeing the issue where the screen will not come on unless you unplug everything and reboot the machine. It's been very frustrating.

I am having the exact same issue as nyec2016.   Dell support has not been any help.   Has anyone found a solution?

@tezken were you having the problem where the monitors randomly go black for a second or two?  When you say the adapters can you be more specific.  What adapters are you referring to?

So I had the exact same issue and saw this post which ended up fixing the issue for me

"Check the adapters. These are bad out of the box sometimes. We were using a DP --> DVI adapter that came with the computer and only the HDMI port was displaying on one monitor.

We swapped out the DP -->DVI adapter with one being used on another computer (same model: optiplex 3040 with only HDMI and DP, no VGA port available).  

Now both monitors work! :)"

YOU FIXED MY ISSUE!!!!! Thank you thank you thank you