U3011, no wake after DP enters sleep mode

Hey guys, I figured this one out. After a couple of weeks of scratching my head, unplugging the monitor, soul-searching, et cetera, I finally have made a conclusion. And I think this is a solution for everyone! Get this, it's the CABLE. Monoprice cables are not compliant with VESA 1.1a for DisplayPort. Try Circuit Assembly cables, they ARE!!! I don't know where you guys have been getting your cables from, but test this theory out. I'm convinced and I have put my order in.

Let's hope.

"A cable is a cable is a cable..." I don't think so man. Checkout Apple's own knowledge base article on this issue:

support.apple.com/.../TS3533

"Certain cables advertised as being VESA 1.1a compliant may contain a construction issue that may result in the DisplayPort power pins at either end of the cable shorting together. VESA 1.1a compliant cables must isolate the DisplayPort power pins at either end of the cable.

To learn more about the VESA 1.1a DisplayPort Interoperability Guidelines, visit www.vesa.org."

This might explain things since I was also using the Monoprice cables.  I have a somewhat unique situation, having 6 of the U3011 displays being driven by 6 Mac Minis. I bought one of each to test, tried a few different cabling options, settling on the Monoprice minidisplayport to displayport configuration after working out that you need to disable DDC/CI.  Once I had that solved, I ordered the other 5 systems for installation.  However, I discovered some worked and some did not.  I switched around hardware and to the best of my knowledge the problem seemed to remain with the U3011 and did not travel with the Minis.  Maybe others can speak to the consistency across components, but I'm more inclined to believe that a cable is a cable is a cable -- that if one works the others will work too -- while monitors can be built with whatever parts are in the supply chain at the moment.  In any case, I'm reasonably certain that the problem lies with the Dell displays, not the other components.  

Eventually, I solved this problem with smart surge protectors, with the power to the monitors switched off when the Minis turn off.  I have three systems on one surge protector, with one of the Minis acting as the master system, all of the monitors on switched outlets, and the other two Minis on "always on" outlets.  The Minis are scheduled to switch on and off via the Energy Saving control panel.  The powering down of the switched outlets seems to have the same effect as unplugging the monitors and that answers my needs.  As I mentioned, this is not your normal installation.  I'll have these six systems mounted on a wall, running 8am - midnight, cycling through images.  But maybe this can help someone else.

www.flickr.com/.../72157626824825533

Display is waking with Circuit Assembly cable. Case closed!

The company is Circuit Assembly, their address (naturally) is circuitassembly.com.

The cable I got for my Mac is:

estore.circuitassembly.com/.../Mini-Displayport-to-Displayport-Adapter-Cable.html

However you might want a full-sized adapter on both ends...

I have this exact same issue on my brand new Lenovo T420 (didnt have the problem on my old Lenovo T61).  However granted the T61 used the dual link DVI.  The newer T420 laptops dont have dual link DVI, only has DisplayPort for 2560x1600 resolution support.  So I used the supplied DisplayPort cable that came with the Dell U3011 and it works except as this thread talks about, the sleep/wake is a problem.  My monitor is set to sleep after 10mins (Windows7 OS).  And it NEVER wakes it.  Sometimes I can open the lid of the laptop, then close it and then it wakes the U3011 fully.  Other times when that dont work, as another person mentioned, Im forced to undock and redock.  Disconnecting and reconnecting the DisplayPort doesnt work either.  

I guess I can try what ovedtuo is suggesting of getting the Circuit Assembly Vesa 1.1a DisplayPort cable (In my case I need full size male to male displayport connectors) but it somewhat ticks me off that I spend over $1200 for this monitor and the supplied cable (if that truly is the fix) isnt even a correct 1.1a certified cable.

Im with what other person mentioned, there needs to be a firmware fix for this.  I cant disable DDC/CI (dont know how or see no options on how to do this on Windows 7).  Somewhat amazing (I work in a software company and deal with QA dept all the time) that they never tested sleep/wake on displayport cable.  Its clear that folks on Mac, HP, Dell, even me on Lenovo having this issue.  So clearly its not the laptop/workstation at fault.

Dixit

Yea undocking and redocking is not a fix, not even a workaround, its a flipping pain.  Especially when Im working (i work at home through VPN) and when I undock and redock, I lose my VPN cause i just killed the network.

I do plan on getting that cable in the link you showed, probably the 6ft one.

Dixit

Well that ***, I cant buy any black cable no matter what length.  Only one available is the 3ft green. I dont care about color, but 3ft aint going to cut it.  Need 6ft.  Back to drawing board.  On a sidenote, I ordered a DisplayPort to Dual link DVI active adapter.  One of these guys

Why?  Well I have this DVI (dual link capable) KVM I use for my other computers with this monitor.  When I got this T420 it somewhat *** me off that the dock has a DVI but they dont make them with dual link DVIs, only single link.  They recommend using these DisplayPort to DVI active adapters.  So since I still want to go back to using my KVM fully (instead of now where I need to use the KVM for just keyboard/mouse and use the monitor itself for switching from DisplayPort to DVI) I decided to get one of these.  Hopefully I dont have issues with this $100 flipping adapter.   Otherwise its going back.

Dixit

I just use a regular display port cable.  Is this the cable you plan to buy/try ?

estore.circuitassembly.com/.../Premium-Displayport-Cable-3-to-10-Ft-Nylon-PolyBraid.html

The six foot cable in black?

Please let me know if the "Circuit Assembly Vesa 1.1a DisplayPort cable" fixes the issue.  I still undock and redock my Dell Latitude E6420 whenever I need to use my computer. 

Well, I went ahead and ordered the 3ft. green cable.  Fingers crossed it is not a gimmick and waste of my time.  

estore.circuitassembly.com/.../Premium-Displayport-Cable-3-to-10-Ft-Nylon-PolyBraid.html

I wish Dell would look into this matter.  Maybe next time I buy HP...

I got my fingers crossed for you as well.  If it does work, Id call up customer support and ask them to pay for your cable.  Clearly they seem to refuse to believe there is any problems with the monitor.

If my DVI DisplayPort Active adapter doesnt come in time, then I going to need to order the same cable.

Dixit

Guys I have been busy. Sorry for not posting sooner. The CA cable helps, but the handshake still breaks when you sleep your computer for more than a few minutes. Whereas the cable from mono price wouldn't even wake the display if you let the display fall asleep for a second (while the computer is still on) the handshake would be gone, the cable from CA initially was the fix. Even if you slept the computer and woke it up after a couple of minutes, it worked fine. So I reported this was a fix. But when I woke up the next morning and went to wakeup my computer, no dice. I was so disheartened I just gave up on Displayport. I have since switched to Apple's mini display->Dual Link DVI, which I found used on EBay for $40. But guess what. Even though that wakes up the monitor every time, about half the time the screen is covered in snow and you have to put the monitor to sleep and wait a minute for the proper picture to come up.

This is very confusing I know. I think what this might mean is that there is indeed something screwy with the handshaking in Dell's firmware, but also cables from Monoprice are of subpar quality at least for this kind of cable.

Wish I had waited and bought Apple's Thunderbolt Display or something. Oh well.