After the time spent with Dell Support doing diagnostics and updating video drivers to those official Dell drivers on the support page, my new XPS 15 9550 with 4K touch display continues to struggle when using external monitors. I have two (2) Dell U2515H monitors.
I have updated ALL of the drivers and BIOS to the very latest files available on the Dell support page, including the newest Thunderbolt 3 driver.
When the laptop is NOT connected to any external monitors, I am NOT experiencing any trouble.
When the laptop is connected to ONE external monitor via the onboard HDMI port, I am NOT experiencing any trouble.
Trouble begins with the addition of ANY external monitor via the USB-C/Thunderbolt 3 port.
I have experimented with the following three adapters, all producing the same result:
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.
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.
XPS 15 (9550) - 4k / 512GB
Good afternoon. I have same issue. I believe I fixed by checking the "do nothing when lid closed" not only for when plugged in but also when on battery. I believe has to do with the charger in the dock not providing enough power. Seems silly given that my XPS 15 and the TB15 Dock are marketed together. Hope there is a fix soon as i really do not like that setting.
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!
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.