(TL;DR) If you are experiencing issues matching one of the descriptions below, please send me a Private Message!

I bought a new Dell Precision 7510 in October 2016, and it didn't take long for me to notice that the TrackStick will occasionally stop responding. This is most noticeable when clicking-and-dragging, for example, when selecting text or moving a window. In general, the TrackStick is not completely unresponsive when this happens - sometimes it just stutters a bit, sometimes it freezes completely but letting go of the mouse for a second or pushing the TrackStick really hard will make it respond again. Regardless, the problem is incredibly annoying and disruptive to my work. There are also occasional problems with the TouchPad - sometimes clicking a TouchPad button while I have a finger on the TouchPad would cause the pointer to jump to the bottom right corner of the screen and become unresponsive for 1-2 seconds.

I contacted Dell Support, and they sent me a new Palm Rest and Keyboard. The new Keyboard didn't seem to have any impact on the behavior, but the new Palm Rest did. With the new Palm Rest, the TrackStick freezes happen much less frequently (although they do still happen occasionally), but the TouchPad will freeze periodically (at about the same frequency as the TrackStick freezes on the original Palm Rest, but without the pointer jumping to the bottom right corner of the screen as with the TouchPad issue on the original Palm Rest), and occasionally the TrackStick will move the pointer (I used some very low-level debugging tools to determine that it was the TrackStick causing these movements) as if it were being touched when my hands are nowhere near the TrackStick (like when I am holding a phone with one hand and typing on the number pad with the other hand).

As it turns out, I also had several other unrelated issues with the laptop, so Dell eventually just sent me a whole new laptop. The new laptop solved all of my other unrelated issues, but the new laptop still had the same TrackStick/TouchPad issues as the original laptop with the original Palm Rest, although on the new laptop the mouse issues happen even more frequently. However, swapping either of the two Palm Rests from the original laptop into the new laptop made the new laptop behave the same as the original laptop with the same Palm Rest.

After months of troubleshooting, I’ve learned a number of things (that apply to both laptops and all three Palm Rests):
* The mouse issues occur in both Windows and Linux, and the triggers and symptoms (for any given Palm Rest) are identical in each OS (although the triggers and symptoms vary slightly between different Palm Rests). Using debugging tools in Linux, I am able to confirm that the Alps device actually stops sending hardware interrupts when the pointer stops responding. External mice are unaffected – when the TrackStick or TouchPad is frozen, an external mouse continues to work fine.
* The mouse issues occur much more frequently when there is high-frame-rate video activity on the Intel video card. For example, scrolling a web page with lots of animated advertisements on it will often cause the mouse to become briefly unresponsive. Opening a command prompt and running a command that prints lots of output, or running an OpenGL benchmark on the Intel video card will typically cause the mouse to become almost completely unresponsive as long as the command or benchmark is running. However, simply playing a video typically will not cause the mouse to become unresponsive (I presume because videos have a fixed frame rate that is not high enough to trigger the issue).
* High-frame-rate video activity on the nVidia card does not trigger the issue. Disabling “Switchable Graphics” in the BIOS (which disables the Intel video card and forces the nVidia card to be used instead) effectively fixes the problem. However, unfortunately, using the nVidia card also dramatically reduces the battery life and makes the laptop generate much more heat.
* The mouse issues do not seem to be affected by CPU/Disk/Network/other activity. Only video activity seems to correlate with the problems. For example, opening a remote desktop to another machine and running a command in a command prompt on the remote desktop that prints lots of output is sometimes enough to trigger the mouse issue on the laptop.
* The mouse issues occur much more frequently when the laptop is running on A/C power than when it is running on battery. The issues do still occur when running on battery, but much less frequently. Plugging in an A/C adapter with neutral and ground connected but with the hot wire disconnected behaves the same as running the laptop on battery. (Indicating that this is not simply a ground noise problem when using the A/C adapter.) Plugging the A/C adapter into a UPS or an isolation transformer or a stand-alone generator does not change the behavior relative to plugging the A/C adapter directly into commercial power. (Indicating that this is also not a problem with noise on the hot wire.)
* Removing all Alps drivers and forcing the TrackStick/TouchPad to run in PS/2 compatibility mode seems to make the mouse issues occur much less frequently. However, this also disables all of the multi-touch and scrolling capabilities of the TouchPad/TrackStick.
* I’ve tried many different versions of both firmware and drivers in both Windows and Linux, and the issue is the same with all of them (as long as the Alps device is not switched to PS/2 compatibility mode). Other than the “Switchable Graphics” setting, no other BIOS settings seem to have any impact on the issue. In particular, the C-States and SpeedStep settings DO NOT change the behavior.

A couple months ago, my Dell Support case was escalated to the Dell “Resolution Expert Center” (or “REC”), and they got some Dell engineers involved. However, since then, things have pretty much stalled. I sent the REC my original laptop with its original palm rest, and gave them several test cases to try to reproduce the issue. They were able to reproduce the issue by running “for /l %a in (1,1,1000000) do echo %a” in a command prompt. However, their engineers responded to that with some nonsense about a 'for' loop being unsupported “syntax that has been built for third party purposes” (what does that even mean?) that is “possibly allocating the wrong amount of memory when running this command causing the system to become intermittently unresponsive.” (I can demonstrate that it is not allocating the wrong amount of memory, and I can also demonstrate that this command doesn’t cause issues on many other Dell laptops, but they refuse to discuss this particular command with me any further.) They also claim they were unable to reproduce the issue by running any of my other test cases. So, I recently had them send me back the original laptop (thinking maybe they found some magic firmware update, driver update, setting, or something else I’ve missed that makes the issue go away for everything but the “for” loop), only to discover that they hadn’t even installed one of the OpenGL benchmarks I asked them to test on it. At this point, they are telling me there is nothing more they can do for me, in part because they have “no other cases in the REC like this as we track potential systemic issues.” However, I have found a number of similar complaints about the TrackStick and/or TouchPad on Dell Precision 7510 laptops around the web, so I’m confident this issue isn’t isolated to my two laptops. I’m hoping to get the REC/engineers to take one more stab at reproducing the issue with one of my laptops. However, I think it would also help to gather reports from other users experiencing the same issue.

If you happen to have a Dell laptop with symptoms matching my description above, please send me a Private Message (Go to http://en.community.dell.com/user/conversations , click “New”, and type “TopQuark_net” in “Recipients”) so we can make sure your issue gets reported to the REC. If you have problems sending me a Private Message, please post a response to this thread.

Keywords: TouchPad TrackPad TrackStick PointStick