Dell U2715h not working with Mini Displayport

Hi all,

I have a brand new U2715H that I have installed today and it has MDP to DP cable but it doesn't work, there is no picture. It says MDP input selected but the screen stays black. I have tried restarting the computer and I have tried pulling out the power cable on the monitor, and the MDP cable and restarting the computer but I cannot get a picture. HDMI works but only on one of the HDMI ports. I am going to send it back tomorrow but thought to ask if someone else had seen this issue, I did a search on the web and see some posts about this but no solutions as yet. Tried a few things in OSD such as enabling 1.2 or disabling but doesn't change anything.

Just to be clear: you have the Displayport end of the cable plugged into your video card, the MiniDisplayport end plugged into the monitor, and in the monitor's OSD you have chosen MDP instead of DP? What exactly is the Displayport end plugged into?

Displayport plugged into gtx770 on Windows7 64bit, MiniDisplayport plugged into correct (and only one it fits in) socket in the monitor. OSD I have chosen MDP.

This may sound like a dumb question, but does it show up in display properties? Can you enable it?

AMD T-type said:

This may sound like a dumb question, but does it show up in display properties? Can you enable it?

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It does show up. It's weird because I can get the dp to work after all. I was getting a blue screen with a moveable cursor and then I realised this was one of two screens (in my previous setup I was using two screens). So I made one screen the default and DP worked!

So it works seemingly fine, but then I reboot, I see bios and post on the screen and then it goes black. It is in power save mode. There is nothing I can do. I suspect I could switch to hdmi, log in then change to dp but once I reboot, it's gone and it's flakey at best.

So what I did after I booted up in dp mode and had the black screen where I wanted to see my Windows 7 login, I changed to my old DVI monitor. Once plugged in, the screen said 'nothing detected' and it said 'entering power save'.. So I had to restart my computer (dirty shut down)! Should me plugging in dvi have made my computer see the monitor without reboot?

I am thinking, is it a faulty monitor (which I have just sent back) or is there something wrong with my OS? I still suspect it's the monitor and will see next week.

I had a Dell P2715Q with very similar symptoms to what you're seeing. The mini DP mode would be dark while HDMI would be fine (I couldn't switch to DVI because my video card doesn't have a DVI connection). It was very frustrating. Ultimately, I discovered that the defective gear wasn't the monitor but the Dell mini DP cable. Like you, I also ordered a replacement but when I hooked it up, it had the same "no picture, entering power saving mode" problem. I couldn't believe two monitors in a row would have the same fault and on a hunch, I swapped out the mini DP cable I had been using with the one that came with the replacement monitor and voila - the screen lit up. I put the original mini DP cable back and the monitor went dark. This was two months ago and haven't had any issues since. You already returned your monitor but did you keep the mini DP cable? If you still have it, use it to hook up your replacement monitor. I'd be curious to know what you see.

ddarko said:

I had a Dell P2715Q with very similar symptoms to what you're seeing. The mini DP mode would be dark while HDMI would be fine (I couldn't switch to DVI because my video card doesn't have a DVI connection). It was very frustrating. Ultimately, I discovered that the defective gear wasn't the monitor but the Dell mini DP cable. Like you, I also ordered a replacement but when I hooked it up, it had the same "no picture, entering power saving mode" problem. I couldn't believe two monitors in a row would have the same fault and on a hunch, I swapped out the mini DP cable I had been using with the one that came with the replacement monitor and voila - the screen lit up. I put the original mini DP cable back and the monitor went dark. This was two months ago and haven't had any issues since. You already returned your monitor but did you keep the mini DP cable? If you still have it, use it to hook up your replacement monitor. I'd be curious to know what you see.

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Thanks, this is a very interesting reply to read. Unfortunately I was unable to keep the cable, the company I bought it from insisted I sent all back as it was in the box originally.

I should have the replacement in the next few days, I will let you know. If I do have the same symptoms I will go for plan B and buy a DP cable (probably not mini, just dp -> dp) and then see if it's working. If it's still not working after that I will reinstall my system completely and then if it still not working, I will go for another monitor. Shame though, liked the screen on 2715 (hdmi), was a perfect upgrade from my 2407. Kinda would have been nice to have 2 of them! I considered the 3415 for a long time but I feel my rig is not up to it so will be for next year..

I'll post more when I can.

Be sure to keep 1.2 enabled if using the small connector port.

FWIW I am having almost exactly the same problem with my U2715H. The only difference is that in my case, for a few weeks the display would work at least some of the time. It would go blank randomly and boy was that annoying. As of a few days ago I get no picture at all, and only occasionally does even the on-screen menu show up. More often the buttons do nothing.

This is my second monitor. The original one went back under warranty. I tried to get a second warranty replacement today, but Dell wanted me to jump through all sorts of hoops because they seemed sure I couldn't have possibly gotten a second defective monitor. Since I already got a replacement video card and the cable is new as well, I don't know what else the problem could be.

I'm pursuing a refund, as I have better things to do than troubleshooting and repeated warranty claims. What a pain this has been.

Update: Never did get satisfaction using the miniDP input. Eventually I got sick of messing with Dell tech support & shelled out for my own regular DP to DP cable. Life has been good since.

Further details in my own thread here: http://hardforum.com/showthread.php?p=1041922544#post1041922544

Thanks for updating there Object!

I must admit it is a very nice screen and I have no doubt nearly all the issues are caused by the crappy minidp cable they supply with, which is very shocking on Dell's behalf.

As to what happened to me, I was so annoyed I sent it back and just cancelled.

Few months later, last week actually and I for once bought a non Dell and went for an Asus pg279q. And well, I played the lottery and lost, dead pixel and dirt under screen and the usual IPS glow but seemingly worse so I sent that back.

This is all getting very tiring. I am thinking about 2xdell u2715 or even 2 x u2415 if they are 16:10. Or I wait for new one from Dell out soon. I will be using for games, movie watching and music production. There is nothing wrong with the U2715 apart from the cable (there is a little glow here and there), it's a very nice monitor.

Thanks! The really surprising thing is that I seem to have received two defective DP-mDP cables in a row. Either that, or the mDP input in the monitor was defective on the first one. Possibly the miniDP port in the replacement monitor is also defective.

I've seen other Ultrasharp owners advise doing RMAs until you get hardware revision A03. Some have reported problems using the regular size DP input as well as the mDP input. Maybe I'm "lucky" because I have an A02 that works on regular DP?

At one point I just wanted a refund because I was so tired of messing with the whole business. But I really couldn't find a different display of the same size and resolution, and IPS panel (seriously, I don't think I ever want another TN!) that seemed like a better deal for the money. I've won the "dead pixel lottery" twice in a row now - no defective pixels or uneven backlighting on either the original monitor or its replacement. But that's part of what you pay for with an Ultrasharp, isn't it?

It will be a week or two before I get the new cable. I'll post again when I've seen whether it works.

Just got a ship notification on the new cable. That was faster than I expected.

Commodore64, have you had a resolution to your situation? I may have missed it but I just re-read the thread and it sounds like you still don't have a working display.

Buying my own DP->DP cable "fixed" my display, but if the new cable arrives and I still can't use the mDP input, I'm doing another RMA. When I shell out for an Ultrasharp, every input better work.

No solution at the moment, I am still waiting for the refund for the asus, but I am leaning towards getting 2x2715h. Will definitely ask for latest revision (A03 I think) if I do that. You had two bad cables, this is the common cause, hopefully they sorted it out. I think the lottery is less with Dell, it's probably between asus/acer/benq and Eizo in terms of quality although I would say it matches Eizo in some models in their upper range for photography etc, some very nice monitors.

So no working solution but I do have a working display, my trusted ol' Dell 2407. Which has some large blotches when you see a white screen but I still love it. But it's time now..

Dell must have overnighted the new DP-to-mDP cable, because it was waiting for me when I got home.

So either I now have a third defective cable, or the mDP port on the monitor is bad, because I still get no picture when using the new DP-to-mDP cable. Not even after turning the computer completely off and on again, restarting it, and turning the monitor off and on a few times.

As soon as I once again connected the monitor via the DP-to-DP cable I bought, it worked fine again.

Sigh.

Another replacement monitor is supposed to be on its way soon. Maybe I'll get the mythical hardware revision A03 and the mDP input will finally work.

Wanted to bring this thread fully up to date.

I am now on replacement monitor #3. It is still hardware revision A02, but this time everything works.

Here's a synopsis so you don't have to go digging through the other threads:

The last monitor I posted about in this thread proved to have a defective miniDP input, just like the first two (as shown by having replaced both the video card and the miniDP-to-DP cable).

That second replacement unit came with all inputs working but...the casing was misaligned with the back USB port, so that the port was unusable. Which is how I ended up getting yet another replacement monitor, bringing me to replacement #3, and monitor #4 overall (counting from the monitor originally shipped from Amazon).

Astonishing, and not in a good way. But at least I have a fully working monitor now.