Trouble with XPS 15 9550, USB-C/Thunderbolt 3, and external monitors

I have the same problem with XPS 15 (9550) with three 4K monitors (all from Dell). This is a very frustrated situation.

I STRONGLY URGE DELL TO FIX THIS PROBLEM APSP.

I have the same problem with a DisplayPort connection using the XPS 15 9550 and an external display. Are you running Windows 10? I've speculated that the half completed Control Panel ==> Settings overhaul isn't fully blocking the "closing the lid" power-management functionality, even with the "Do Nothing" setting in vogue. The laptop may be erroneously and ineffectually sending the signal to the display to sleep. But if the same problem exists in Windows 8.x, then that theory seems unlikely. It's a pity Dell doesn't offer the option in BIOS to select what the laptop does when the lid is closed.

I have the TB15 Dell Thunderbolt Dock too. Whether I connect the  DisplayPort cable to a Thunderbolt 3 adapter or the Dell Thunderbolt Dock the results are the same. I don't think the Dock plays a role. You say the blinking off and on problem doesn't happen with HDMI, that would indicate that the Thunderbolt 3/USB-C port, or more likely its controller software (which Dell updated only a few days ago), is at fault. I suspect Dell will get this ironed out in time. They are really good about updating their drivers, firmware etc. But they need to know about the problem.

I contacted support and had a very long dialogue with them that lasted over a month. But because my machine is 4K and my external monitor is 4K, I never thought to use the onboard laptop's HDMI 1.4 port, which does not support 4K at 60Hz. But I'm going to try it tomorrow. By the way, it's definitely not your monitor. I've experienced the same problem with three different Dell 4K monitors now.

I'd appreciate it if you came back and posted what version of Windows you're using.

Further info:

• I'm running Windows 10 Pro 64 bit.
• I updated the Intel video driver to the latest direct from Intel by deleting the Dell driver. Didn't help. For now, I've rolled back to the latest Dell issued Intel video driver.
• I rolled back on the nVidia driver to the latest Dell issued version. Didn't help. I've since let that driver automatically update to the latest direct from nVidia.
• I was hopeful when I saw the new Thunderbolt 3 driver. Didn't help.
• I noticed that the max resolution on the Dell DA200 "mini-dock" HDMI port is somewhere below that of the dedicated USB-C to HDMI cable. The DA200 didn't reach to the native resolution of my monitors, which is 2560x1440. Disappointed in that, as I liked the idea of it and gig ethernet port running simultaneously. One fact on this front is that when I had the DA200 connected via HDMI to my 3rd screen AND the ethernet port in use, the ethernet port also went flaky when the display events occurred. Really, really strong evidence of a Thunderbolt 3 problem, right? I'd be curious to know if those using the new Thunderbolt docking station have noticed the other ports going flaky during the display events.

I've temporarily given up on the Thunderbolt 3 port. I ordered a Plugable USB 3.0 to 4K HDMI that does 2560x1440 at 60 hz (DisplayLink drivers). I've always had great success with my Plugable video cards and, while waiting for UPS, I'm presently using an older Plugable USB 3.0 to DVI unit connected to an older monitor as display #3. No problems whatsoever and no crazy fan speeds. In fact, except for which ports are being used, I'm set up and stable the way I hoped.

I have some confidence that Dell will get this fixed. In fact, I kind of blame Intel - it's their chipset and tech. Perhaps that is what I deserve for being ahead of all the accessory set for the USB-C/Thunderbolt 3 port. I see that even noted Googler, Benson Leung, who had taken it upon himself to 3rd party validate USB-C cables, was burned (literally) when a shoddy cable fried his beautiful Chromebook Pixel and several pieces of kit connected to it.

So, I'll fix my immediate problem and wait for Dell to fix theirs. I have plenty of adapters to choose from when that magical Thunderbolt 3 port decides to work (without turning my fan into a drone motor).

I can confirm this problem.

I have a USB-c-To-Ethernet adapter and when this device is plugged in, the fans will continuously run untill I unplug it.

System Information:

XPS 15 (9550) - 4k / 512GB

Bios: 1.1.19

Drivers up-to-date

Hi. Some conflicting information: Like you, I have my "set what happens when lid closes" setting on "do nothing" for both battery and AC power, but I still have the problem that with the lid closed, the monitor blinks off for about five seconds and then back on, repeating that miscue every 3 to 4 minutes. My experience has also been that the issue has nothing to do with the TB15 dock. I can also use a DisplayPort connection that starts with an adapter plugged in to the USB-C/Thunderbolt 3 port. I have the same problems in that configuration as I do connected to the Dell Thunderbolt Dock.

So, that said, if you have solved the problem, can you think some more about how you did it? I'm sure that all of us and many more besides would really appreciate your information!

In my instance, I do NOT close the laptop lid. My laptop is placed directly in front of me and I have one Dell U2515H to my right and one to my left. I have not experienced any issues with the laptop lid side of this problem.

The problem is actually worse then just the fan running.. try plugging in a usb keyboard, wireless or not and a wireless USB mouse..  The mouse skips around and the keyboard either misses characters or it repeats characters randomly.  the system acts as if it is being overtaxed and is unable to perform well.. everything goes much slower and struggles.  And yes I have all drivers and bio updates.. Dell claims I'm not using compatible port replicators.. but i bought the one linked to the 9550 page.. Then they tell me this is not compatible since it shows only latitude compatibility.  The version of DA200 that is compatible is only available in singapore?? strange, all of this.

DELL - are you listening to all the comments about this issue??  You have a major issue on your hands.  If I didn't like everything else about the laptop I'd return it in a heartbeat.

I, too, can confirm this problem.  So long as my Thunderbolt adapter is plugged in, I get screen flickering, window resizing, etc. about every 10 minutes.  Very frustrating.  I am eagerly anticipating the fix for this.

I've been having the same issue with my TBT3 port. I have a TB15 docking station and it's not useable because of the TBT3 issues. The dock will just loop through connecting and disconnecting.

I've been using a usb-c to hdmi converter with a bit better luck. It will stay connected but does like to flicker every so often which is very annoying.

I look for new drivers everyday, nothing has worked yet.

XPS15(9550)/i7/16G ram/500G SSD with Thunderbolt 3 dock: 2 external HDMI monitors with lid closed is my normal cfg.  Sometimes a monitor will go dark and not come back without power cycle; random monitor resync and USB disconnect and reconnect. This happens every few minutes, not just once in a while. Although it did seem to happen a little less when the audio drivers were updated last week.

I check for new drivers every day, hoping that someday this silliness will get fixed. Until then, the XPS15 with TB dock are pretty much a useless configuration.

I have XPS 9550 and TB15 dock but only one monitor for the moment (have not tried yet with several) connected with display port cable. I have not had any issues so far with the monitor but the fan speed is pretty annoying. 

If I open or close the lid it works as it should for me.