Kind of an info post & a question.
My new Dell XPS 13 9350 touchscreen started to intermittently fail & within a day or 2 it completely gave up. I also noticed that there was no touchscreen device in Device Manager (under HID section) nor any mystery USB devices there (an Internet search reckoned it could be a power problem). I did notice though that under USB Devices section there was a mystery device that said "Unknown USB Device (Device Descriptor Request Failed).
Called Dell Support who informed me that since it was purchased from a UK retailer I wasn't eligible for Dell support! So I called PC World...
They took me through a step which I'd already tried (uninstall & reinstall mystery USB devcie) but this time it worked - touchscreen appeared in HID section & mystery USB device vanished. Hung up the phone, moved laptop then the touchscreen failed again. This time, on loading Device Manager, it was unusable. Device Manager kept refreshing over & over again, but I did have time to see that again touchscreen had vanished from HID & the mystery USB (with same message) appeared in USB Devices. This time though the USB device would vanish & then the screen refresh.
A bit more Google searching revealed that a touchscreen is effectively a mini USB device & I wondered if the issue I was having was due to an intermittent connection. It would explain the constant refreshing of Device Manager since it was like something being connected & disconnected constantly.
A final recovery to factory settings & problem still persisted so I concluded it was a hardware issue.
As it was only 2 weeks old, I was offered a refund since no more stock & I'm now awaiting delivery of the new XPS 13 9360 from Dell.
I'm a bit concerned that this happened & curious if this is a common feature of touchscreens & if it was to happen again to my new model is there an easy fix (once out of warranty).
Hope the above helps somebody with a similar problem!
Rather unfortunate you had to face issues with a new system.
Even if the system was purchased from PC World, if the order was shipped with Dell warranty, then it does hold good with Dell to get a service call on the system.
Regarding the LCD issue - I suppose it might have been a loose LCD cable issue that was causing the intermittent touchscreen functionality and even more that it would work / stop working when the LCD is moved.
Reseating / replacing the LCD cable (unless part of the assembly in certain models) should ideally resolve such issues.
Hope the 9360 model brings you good experience.
Should you need any info / help, contact us anytime.