TP770: strange cursor drifting issue

[landsmarra]

Hello!

If my TP770 9548-30U is turned on while plugged in or on battery, the trackpoint mouse pointer works perfectly. If the PC is then unplugged while it's on, the mouse pointer will begin to drift on its own either up or down. If you move the pointer, as soon as you let go of the pointer stick, it will continue to drift. Rebooting fixes the issue. FYI, this also happens if the PC is on battery and is plugged in while operating.

I'm using the latest Win98 trackpoint driver from the IBM/Lenovo site.

Any clues? It's very annoying! Thanks!

[landsmarra]

Update:

Now it's drifting every time I boot it up! Even does it on the Easy Setup screen.

All I did was to install a new WLAN PCMCIA card but it did it even before that...just not consistently.

I've tried booting with no battery and no PCMCIA card to no avail

Ugh!

[virge]

Try letting it sit for a few minutes when the pointer starts to drift. I believe the Trackpoint is designed to re-zero it self. Seems to work with my Thinkpads... except for one. That one I had to replace the Trackpoint.

[Brad]

If you have a different keyboard I would try it.

Brad

[landsmarra]

OK, I'll try letting it alone to recenter, we'll see!

Also, don't have another keyboard to try, Brad...need to check eBay unless a member here has a spare. I'll check the marketplace.

[virge]

"Cursor drift is a ubiquitous problem among pointing sticks, requiring frequent recalibration. However, TrackPoints automatically recalibrate when the stick recognizes a steady cursor drift; to trigger a recalibration, the user must lift his finger temporarily off the TrackPoint for about 1 second."

Sorry the quick and dirty. (from Wikipedia )

[landsmarra]

Thanks for this info! I'm obviously not touching the trackpoint stick while it's drifting and I can watch if drift for a good 15 seconds before it gets to the bottom/top of the screen. After it gets to the bottom, if I move it back to the middle of the screen, it drifts back down.

Therefore, I'd say it does not appear to be recalibrating after a second unless I missed the point

[vanaya]

I have had this happen just before I get the dreaded 8611 error on my 600e. I'm not sure it is common for the 770 series but is for the 600's. Sorry for not having any solutions but maybe a prevention.

[landsmarra]

Interesting you mention 8611...I saw that after I updated the BIOS. I rebooted a couple of times and it stopped happening. Of course I thought I hosed the lappy after upgrading the BIOS!

The trackpoint has been working OK today. Occasionally it will drift when the web browser is in the middle of a download but then it stops drifting.

I noted where Lenovo's site suggests reseating the keyboard and trackpoint cables when you get an 8611. Should I try that for laughs? I always hate to disassemble something unless there's good reason

[vanaya]

I've never touched a 770, but re-seating the keyboard never worked for me on a 600. Also on the not sure side, can you disable the track point in the bios like you can on the 600? Just to save the keyboard.

[u.mac]

I've never touched a 770 - but I think, if there's no issure after boot from a linux-live-cd, the trackpoint is ok.

Take out all extensions, disable all ports, than take a new try with W98 - and take away any cell-phones, wifi, wlan, bluetooth, radio-remotecontrol... disable power-LAN in our home, and use 770 on battery.