will.box @Chromatics I can confirm I have two 4k monitors up and running, one mDP and one DP. Once I solved the heat issue with a fan I had no issues. Haven't had problems with USB or network connectivity either aside from it sometimes taking a bit for things to wake up after bring the laptop out of sleep mode.  I didn't mess with HDMI for very long because I found 30hz to be unacceptable performance wise and agree seems silly that they didn't use HDMI 2.0 on this thing. I was having USB issues when I was briefly using HDMI but I believe that was before I had applied a round of driver updates.  What did you do to resolve the heat problem?

If you go back through this thread I posed a picture of my laughable setup, but basically just have the dock sitting on top of a little desktop fan. I believe somebody else said simply having it on its side also helped. Either way it seems there is a very fine line between it hitting a heat threshold and crapping out because there is no way what I'm doing is cooling anything that much. 

If I keep my lid open, everything is still rock solid for me, 3 screens(mDP, DP, HDMI), USB, and network.  BUT ONLY if I keep my lid open.  As soon as I close my lid I either get no video, no USB, or I can occasionally get my screens to come on but then they just shut off.  I can't deploy these if the lid needs to be open.  Our end users are use to keeping the lid closed. Thanks Chris

There definitely are some heat related issues. Are you opening the case all the way, or just propping it open a few inches?

Both audio ports work for me.  I have a headphone extension in the back of mine.

My display issues are as follows.

-I have two HP 23xi monitors plugged in the dock via HDMI to HDMI and DisplayPort to DVI.

-At various intervals (1-4 hrs.), but I strongly suspect due to overheating, the DisplayPort to DVI monitor will sleep/turn off, while HDMI to HDMI monitor remains active/on.

-If I then unplug the HDMI to HDMI monitor and plug it directly into the laptop it wakes/turns on and all is well.

-If I leave the dock unplugged from the power source overnight (to allow the dock to cool down) my displays seem to work for a bit longer (closer to 4 hrs.).

-I tried propping it up off my desk and on the side to allow airflow underneath to no avail.

-I have not taken the cover/case off at this point to see if that helps.  I suspect it will extend the up-time of both monitors, but won't last forever.  Also, why would I want an open dock sitting on my desk?

-I don't plan to tinker for fear of voiding the warranty.

-Aside from the displays, I have the following plugged into the dock without issue: Ethernet, USB Speakers, Logitech Unifying USB Receiver.

-Ha! As I'm finishing up this post monitor just went out.  It lasted about 1.5 hrs. today.

-Seems like a pretty severe design flaw to make a dock with so many inputs AND power, that is completely closed to airflow without so much as venting it, putting heat sinks in it or putting a fan in it!

-Sure hope they figure this out!

-Please advise if any solutions are found.

Thanks and good luck!

I have my speakers connected via the rear audio port, so it's definitely working for me. I suspect it's a driver or potentially firmware issue. I'd assume you've done this, but make sure you've installed all the updated drivers list on page one of this post.

-At various intervals (1-4 hrs.), but I strongly suspect due to overheating, the DisplayPort to DVI monitor will sleep/turn off, while HDMI to HDMI monitor remains active/on. -If I then unplug the HDMI to HDMI monitor and plug it directly into the laptop it wakes/turns on and all is well.

Are you saying unplugging the HDMI from the TB15 (which you indicate is still working), into the laptop wakes up the DisplayPort monitor?

If so, that's interesting.

I do recall someone in another forum suggesting a setting in the BIOS (something "C" or "C" something) which disabled some sleep operations. They said this made their monitors stable.

You might try disabling that and seeing if that fixes the problem.

Yep, when I unplug HDMI from the dock and plug into laptop the Display Port monitor fires back up...

Pretty sure I've disabled every sleep, power saving, power management option or setting in
BIOS, device manager, EVERYWHERE!  My rig is on full blast max-performance.  So much for conserving energy, ha!

I'll check the BIOS settings again though, thanks!

imremahcp / Dan Switzer> I've been doing the same thing to revive my mDP connection. Actually posted about it at the bottom of this thread in case you want the full detail (last part of my message): Soon to be released new Dell Docks may require BIOS and driver updates on your laptop before use!

This workaround seems to do some type of reset on the DP hub and worked fine until I tried to properly fix the issue by using a different DVI cable to my second LCD via the dock HDMI (still using my HDMI to DVI adapter).

Once I did that, the mDP reset trick stopped working, and also brought about a new issue: no longer able to turn on my first monitor (mDP) after turning it off! The only way to recover the mDP connection at that point was to reboot the XPS.

So my next test was to eliminate the HDMI to DVI adapter on the second monitor by replacing it with a straight HDMI -> DVI cable. The mDP reset trick started working again, but only in some cases -- and still not if I turned off that first monitor (actually a UHD TV connected to dock mDP via mDP -> HDMI 2.0 active adapter). I noticed that if I moved that HDMI cable from HDMI 1 to HDMI 2 on the TV, it would ALSO revive the mDP connection.

I then decided to move the second monitor to the dock VGA so I dug out my old cables, connected a straight VGA -> VGA cable from second monitor to dock. Second monitor comes on.. and guess what? I'm also now able to get a solid 4k 60p 4:4:4 signal on the first monitor! I'm still using the active adapter and have another one on the way along with a better HDMI cable so if this continues to work, I'll just send them back.

So to clarify, my first monitor is the 4k (UHD) display connected to mDP in the dock using an mDP to HDMI 2.0 active adapter. And my second monitor is an FHD display, now connected to VGA in the dock. Never had a problem with monitor #2 -- only problems with monitor #1 when monitor #2 was connected to HDMI in the dock using an HDMI to DVI passive adapter.

Thysanoptera posted this in the other thread:
"Mini DP and HDMI is Port 2, full size DP and VGA are Port 1 on the dock (as seen in DisplayPort Topology in Intel driver). I assume that they are being driven by two separate synaptics chips, vmm3320 and 3330. Port 1 in my case goes off after some time in use (full size DP and VGA goes blank), while there are no issues at all with Port 2 (mini DP and HDMI)".

Based on my testing and what Thysanoptera mentioned, I believe DP hub #2 (vmm3330) used by the mDP/HDMI ports can handle more bandwidth than DP hub #1 (vmm3320) -- DP/VGA. Also makes sense as I would think VGA pulls a lighter load.

More bandwidth = more heat. My dock doesn't feel hot on the outside, but if these issues are heat-related, maybe a good approach would be to try balancing the load -- ie. don't plug two high-res displays into one DP hub. I'm only running FHD 60p on DP hub #1 (VGA), and UHD 60p on DP hub #2 (mDP). I am no longer using HDMI in the dock, and it has been solid at 60p for several hours now (first time since I got the dock ~3 weeks ago).

It might help if people posted which ports on the dock they're using, along with the resolution and refresh rate (and if any adapters are in use). I may be wrong in the idea of balancing bandwidth but it may have been what solved my problems. Again, make sure you're using known-working cables.

imremahcp / Dan Switzer> I've been doing the same thing to revive my mDP connection. Actually posted about it at the bottom of this thread in case you want the full detail (last part of my message): Soon to be released new Dell Docks may require BIOS and driver updates on your laptop before use! This workaround seems to do some type of reset on the DP hub and worked fine until I tried to properly fix the issue by using a different DVI cable to my second LCD via the dock HDMI (still using my HDMI to DVI adapter). Once I did that, the mDP reset trick stopped working, and also brought about a new issue: no longer able to turn on my first monitor (mDP) after turning it off! The only way to recover the mDP connection at that point was to reboot the XPS. So my next test was to eliminate the HDMI to DVI adapter on the second monitor by replacing it with a straight HDMI -> DVI cable. The mDP reset trick started working again, but only in some cases -- and still not if I turned off that first monitor (actually a UHD TV connected to dock mDP via mDP -> HDMI 2.0 active adapter). I noticed that if I moved that HDMI cable from HDMI 1 to HDMI 2 on the TV, it would ALSO revive the mDP connection. I then decided to move the second monitor to the dock VGA so I dug out my old cables, connected a straight VGA -> VGA cable from second monitor to dock. Second monitor comes on.. and guess what? I'm also now able to get a solid 4k 60p 4:4:4 signal on the first monitor! I'm still using the active adapter and have another one on the way along with a better HDMI cable so if this continues to work, I'll just send them back. So to clarify, my first monitor is the 4k (UHD) display connected to mDP in the dock using an mDP to HDMI 2.0 active adapter. And my second monitor is an FHD display, now connected to VGA in the dock. Never had a problem with monitor #2 -- only problems with monitor #1 when monitor #2 was connected to HDMI in the dock using an HDMI to DVI passive adapter. Thysanoptera posted this in the other thread: "Mini DP and HDMI is Port 2, full size DP and VGA are Port 1 on the dock (as seen in DisplayPort Topology in Intel driver). I assume that they are being driven by two separate synaptics chips, vmm3320 and 3330. Port 1 in my case goes off after some time in use (full size DP and VGA goes blank), while there are no issues at all with Port 2 (mini DP and HDMI)". Based on my testing and what Thysanoptera mentioned, I believe DP hub #2 (vmm3330) used by the mDP/HDMI ports can handle more bandwidth than DP hub #1 (vmm3320) -- DP/VGA. Also makes sense as I would think VGA pulls a lighter load. More bandwidth = more heat. My dock doesn't feel hot on the outside, but if these issues are heat-related, maybe a good approach would be to try balancing the load -- ie. don't plug two high-res displays into one DP hub. I'm only running FHD 60p on DP hub #1 (VGA), and UHD 60p on DP hub #2 (mDP). I am no longer using HDMI in the dock, and it has been solid at 60p for several hours now (first time since I got the dock ~3 weeks ago). It might help if people posted which ports on the dock they're using, along with the resolution and refresh rate (and if any adapters are in use). I may be wrong in the idea of balancing bandwidth but it may have been what solved my problems. Again, make sure you're using known-working cables.

To reiterate, I have the following connections.  Not using adapters, just straight cables.

Dock>>>Monitor: HMDI>>>HDMI cable & DP>>>DVI cable

If, as you suspect, the Mini DP and HDMI is Port 2 and the full size DP and VGA are Port 1 AND they are being driven by two separate Synaptics chips, does it stand to reason that if switch to a MiniDP>>>DVI cable I might get more stability? 

We'll find out because I just ordered a MiniDP>>>DVI cable...I'll update next week.

Sounds like what you've got now is already balancing the load. You've ordered a mDP to DVI cable which will put both your monitors on the same hub/port #2; vmm3330. But that's fine given the number of variables at play; software config, different cables/displays etc. In fact, since I posted, things have taken a turn: my second monitor started shutting off, and the first monitor went back to behaving how it was (except the mDP reset trick still works).

Sorry if I mislead anyone, it seemed promising as it was working for the first time and for several hours. My configuration may not apply to most since I'm using an adapter for my 4k (UHD) 60p connection but I'll still update here once I receive my new mDP -> HDMI 2.0 adapter (and overpriced HDMI cable).

I'm doing everything I can to address my non-Dell components... patiently waiting for Dell to step up and address any issues relating to the dock. I'm sure there are still things to be ironed out on that side having seen the complaints here.

imremahcp> port/hub in this discussion refers to the same thing: the Synaptics chips in the dock. Thysanoptera referred to the chips as 'ports', then I probably confused it by calling the physical plug (HDMI/DP/mDP/VGA) a 'port'. Which monitors are connected to your dock HDMI and DP plugs?  

Just got my xps 15 (9550) and TB15 dock and am experiencing the same problems most of you are. Should I keep messing with this or should I send it back. I really don't have money to replace this if dell doesn't fix it before my warranty runs out, but also don't want to return it right before they put out a patch. Is their any number I can call to speak with their support staff, I paid for their "complete care" for the laptop... This is a horrible mess.

Thank you,
Brandon

Sounds like what you've got now is already balancing the load. You've ordered a mDP to DVI cable which will put both your monitors on the same hub/port #2; vmm3330. But that's fine given the number of variables at play; software config, different cables/displays etc. In fact, since I posted, things have taken a turn: my second monitor started shutting off, and the first monitor went back to behaving how it was (except the mDP reset trick still works). Sorry if I mislead anyone, it seemed promising as it was working for the first time and for several hours. My configuration may not apply to most since I'm using an adapter for my 4k (UHD) 60p connection but I'll still update here once I receive my new mDP -> HDMI 2.0 adapter (and overpriced HDMI cable). I'm doing everything I can to address my non-Dell components... patiently waiting for Dell to step up and address any issues relating to the dock. I'm sure there are still things to be ironed out on that side having seen the complaints here. imremahcp> port/hub in this discussion refers to the same thing: the Synaptics chips in the dock. Thysanoptera referred to the chips as 'ports', then I probably confused it by calling the physical plug (HDMI/DP/mDP/VGA) a 'port'. Which monitors are connected to your dock HDMI and DP plugs?

Yep, I misread your post and you didn't mislead!  Like I said, not too tech savvy!  :)  After re-reading it, you're correct, I suppose that I am already balancing the load as you say.

Any news on the fan issues? Anyone....? When can we expect a fix for this? In my case for the Precision 5510.

And to be clear: I mean the fan of the laptop blowing as soon as connected to the TB15 dock :emotion-7:

Don't expect Dell support to be very helpful when you call. I was transferred to 6 people by the time I reached someone who even knew what a docking station was and he wasn't up to speed about this issues what so ever. I plan on sending mine back most likely.