Question DELL Precision M4400 Touchpad/Mouse/Keyboard stopped working.

Jan 15, 2020
Hello there experts
I hope this post finds you in the best of your health and spirits.

So I have a Dell Precision M4400 running on Linux Mint. I love the machine but it has starting acting up now.

The screen was loose and wobbly and the speaker on the right side stopped working.
I was travelling out of country and decided to get it fixed , the person did a great job and fixed the screen and the speaker.

I came back home and after 2 weeks the touchpad stopped working.

I thought maybe it was the cable underneath the keyboard.
I removed the keyboard cleaned the keyboard connector and tiny white cable and reserted it into the cable outlet and the keyboard too stopped working too.

I decided to take apart the whole thing and put it back together by watching videos.

It took me 2 painful hours but i got it disassembled and assembled and the touchpad and keyboard started working.It worked for a good 2/3 days ( but i never found out what the issue was, the keyboard and touchpad started working on its own).

I realized i forgot to put the thermal paste and took the heatsinks off ,applied the paste and when i restarted the laptop and the issue was back.

Im lost as to what the issue it a loose connection somewhere? whatever it is , i dont know why taking off the cooler fan and 2 heat sinks( 1 for cpu and 1 for gpu) made it stop working.

any advice is monumentally appreciated.


Aug 30, 2019
I used to have the M4400, and I understand what a pain it can be taking it all the way apart and putting everything back together right. I never had the issue you're having, but it sounds just like a ribbon cable is loosing connection on one end or another. Maybe got bumped loose during the previous repair. Can't offer much help, other than to say triple check all cables are fully inserted and aren't in upside down, etc.
Jan 15, 2020
yeah i just remembered i did not take the touchpad/keyboard cable out...ill tear apart and do it again..should be easier now

thanks for taking time to respond to my post.
i appreciate it my friend.
Reactions: Remeca