03-02-2019 04:08 AM - edited 03-02-2019 06:00 AM
Anyone know if there is a fuse that protects both the trackpoint and the trackpad on the T440 ?.
Bought second hand and neither trackpoint or pad work. Trackpad shows little wear so I suspect this has been a long term issue.
Booting into Linux there is nothing showing up in the mouse/touchpad settings except when I connect an external mouse, so neither pad or point are being seen, and since they both connect to the mobo via separate connectors it makes me think it might be a fuse ?.
Both are enabled in BIOS and have tried disabling each separately. Also tried a diffferent keyboard, and also disconnected both the touchpad and trackpoint separately. No life from either.
Any thoughts would be much appreciated.
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03-02-2019 07:25 AM
They are USB devices and I believe they are connected along with the keyboard so if the keyboard is working, I would guess a fuse is unlikely, but there are no circuit diagrams available I cannot be sure. Fuses are SMD devices so replacing them requires better equipment than a soldering iron. Are there any problem devices in device manager? Try disconnecting the touchpad and try the trackpoint by itself. There may be a short.
03-02-2019 12:32 PM - edited 03-02-2019 12:34 PM
Thanks for the response richk.
Tried disconnecting the trackpad already, trackpoint still dead. No error messages in Device Manager.....under "Mice and other pointing devices", the usual Synaptics Pointing Device is completely missing, as it was under Linux.
Oddly, the backlit keyboard was working fine before but now isn't, so your theory of a short is looking more likely. Will pull it apart again tomorrow and let you know if anything changes.
03-03-2019 07:51 AM - edited 03-03-2019 07:56 AM
Problem traced to the touchpad ribbon cable - several tracks were found to be open. Confirmed by swapping out cable from my T440s. As an interesting sidenote, the trackpoint will not work if the touchpad is physically disconnected, despite them being on separate ribbon cables. The keyboard backlight issue was a red herring - just a slightly worn connector. Thanks again to richk for the suggestions.