How to stop the track stick mouse pointer drifting into the corner of the screen under Linux

I recently upgraded a friend's Inspiron 8500 to linux and immediately came across the problem with the track stick mouse pointer gliding off into the corner of the screen. This issue is caused by the track stick mouse in the middle of the keyboard malfunctioning, and seems to be a common problem on the support forums.

My friend informed this had been going on for a long time in Windows. He had fixed it with the solution of downloading the latest driver from the Dell support page and then going into the control panel to turn off the track stick input.

However, for Linux there is no real solution I could find. The Inspiron 8500 (and I think most other models that feature the dual touch pad / track stick setup) uses hardware that is not (easily) compatible with the synaptics Linux driver that allows you to tweak the settings. So your mouse will run in generic PS/2 mouse mode and the track stick will constantly move the pointer all over the screen, or leave you fighting it with the touchpad as it scrolls off into the corner and gets stuck there. changing the surface the laptop sits on, or tilting its angle will make some interesting cursor effects and help it get out of the corner, but not for long. In short, the system is totally unusable.

Anyway, after trying EVERYTHING else (BIOS updates, fiddling endlessly with the synaptics driver in synaptics and alps modes), I came across a simple, elegant, 100% effective solution.

f you pull the keyboard out (follow the instructions in the online service manual for your model at support.dell.com) you will see there are two different flat plastic busses that run from the keyboard connector plug to the keyboard. The wider one goes into the keyboard. On this Inspiron 8500 it was yellow. The smaller one (in which you can only see 4 little wires) goes into the keyboard right under the track stick. On the Inspiron 8500 it was purple. Cutting the small one with scissors and putting the keyboard back in did the job very nicely - the track stick no longer could send input and move the pointer into the corner of the screen, and the touch pad works fine by default!

NOTE: Obviously if you do this your track stick will never work again!!! (unless you repair the bus cable somehow). BUT if you are reading this, it is probably already totally broken and stopping you from upgrading to Linux. So you may be Pleased to find out it's a simple 5 minute job to kill the track stick forever, leaving you with an operational touchpad.

That's it really... in case you are not comfortable with the loose instructions above, here are detailed step by step instructions that anyone should be able to perform. If your model is not the 8500 you should take extra caution that everything looks the same in there before snipping something. I suspect though that any Dell inspiron model wijth the dual touch pad / track stick will have the same keyboard in it, or at least one very similar. You can't hurt anything just taking it out to look, can you? :)

Here are the step by step instructions:

1) Gather your tools. You need:
- A fine head phillips (+) screwdriver for the keyboard tools
- A fine flat head screwdriver or a knife or something.
- A pair of scissors

2) Go to Support.Dell.com, and login. If you don't have an account, make one, it's free. Then under Product Support on the right, enter your service tag # (it's printed on a sticker with a barcode on the bottom or back of your laptop). Press "Go"

3) The support page for your laptop should appear. Choose the "System Documentation" link on the left under "Support Resources"

4) Choose your language, and then look on that page for where the Service Manual is. Usually it's under "HTML Documents". Click the right title (PDF Documents or HTML Documents) and then get the Service Manual open.

5) Verify and perform the correct procedure for removing the keyboard.
On the 8500 this is what I did, it will be similar for most models:
- MAKE SURE IT'S TURNED OFF !!!! (if unsure, -unplug it- and -take out the battery-)
- Open the screen all the way so it's flat and facing up at the ceiling
- Pry off the plastic cover where the power button is, by putting the flathead screwdriver in the slot at the left and then prying from left to right.
- Disconnect the cable to the plastic cover and put it aside. The two tiny phillips screws holding the keyboard in are now visible. Unscrew these with your small phillips screwdriver. Careful not to strip them, if you don't have the right micro screwdriver take a drive to radio shack!!
- Now the keyboard is unscrewed, lift it out gently (top to bottom).
- The keyboard has two plastic busses (flat cables with visible wires inside them) that both run into the same plug that is plugged into the mainboard.
On the plug is a little metal clip thingy with a piece of sticker paper attached. Yank on that and it will pull off the connector for you. DO NOT TRY AND UNPLUG THE KEYBOARD WIRE FROM THE LAPTOP BY PULLING ON THE BUSSES. Use the little metal clippy thing, it's there to help you get the plug off.

6) Figure out which bus (wire) is which going from the keyboard to its connector plug:
You should now be holding the keyboard on its own (no longer attached to the laptop) with the two bus wires hanging free and then ending at one plug. Inspect the two busses. One of them will be much wider than the other. They also go to different spots in the keyboard. The smaller bus is for the track stick, and it should obviusly going into right underneath where the track stick is located on the other side of the keyboard. The big bus does the regular keyboard input, it is much wider with more wires inside it than the small track stick bus. On the inspiron 8500, the wide keyboard bus was yellow, and the thin track stick bus was purple.
So, going by the size and position of where it goes into the keyboard you should be comfortable that it is the track stick wire.

7) Cut the small track stick bus with scissors
Once you're satisfied as to which one the track stick bus is, cut it with scissors. Try to make a nice straight cut right in the middle of a straight run of the little wires inside. That will make it easier to repair it should you ever regress back to windows and want it back to life, or you sell the laptop and the buyer wants the track stick even though it doesn't work). You can just leave the ends floating free, or you could use a bit of electrician's tape, it doesn't really matter. I left this one free and it worked fine.

8) Put the keyboard back in
Just reverse the procedure for taking it out. The keyboard and plastic panel connectors can only go on one way, Don't force them on the wrong way!

That's it... the whole process should take you 5-10 minutes. Since the touchpad detects and performs beautifully using the generic PS/2 mouse function, you will be good to go. Hopefully this post comes in useful for the next person doing what I did.

D.

Message Edited by damien.norris on 12-20-2004 02:44 PM