Welcome, Guest

Author Topic: touchpad right button seems stuck  (Read 2245 times)

diegor

  • Newbie
  • *
  • Posts: 9
  • Karma: +2/-0
Re: touchpad right button seems stuck
« Reply #15 on: November 19, 2017, 06:02:24 PM »
Hi,

  no news on the hardware side. I've tried to reconnect a couple of time the pcb button, but it's still not working.
 
  So I've started to study the firmware, to implement some workaround (for example it would be nice to implement button key using the keyboard :) ).

  I've started a fork, and at the moment, it have almost exactly the same features, but the code is reworked for clarity and for being more easy to customize.

  If someone is interested you can find here:

    http://git.trueelena.org/cgit.cgi/firmware/TERES-KBD/

  As I said, atm it's almost identical to original firmware, with only button disabled. I'm modifing the code on the teres with this firmware loaded all the time, so it's usable most of the time (if you don't need the right click).

  It's still need more polishing, but it should be clear where is headed. And of course it's still distributed with gpl license.

  As a last note, thanks for giving access to the firmware! There are not many device where you can actually fix the firmware :) And I hope my work can be useful to others...

Regards,
  Diego.

khumarahn

  • Jr. Member
  • **
  • Posts: 68
  • Karma: +6/-0
Re: touchpad right button seems stuck
« Reply #16 on: November 20, 2017, 07:03:25 PM »
I had a problem with touchpad buttons after the laptop spent some time in humid environment. It helped to re-solder the capacitors underneath the button pcb, and to thoroughly clean everything with alcohol.

There was a resistance on terminals of one of the buttons of approx 11.1K (there should be infinity). It was probably caused by some flux residue/corrosion.

khumarahn

  • Jr. Member
  • **
  • Posts: 68
  • Karma: +6/-0
Re: touchpad right button seems stuck
« Reply #17 on: November 20, 2017, 08:50:47 PM »
@nix, can you unplug the PCB3-TOUCH board from everything and test the resistance on both buttons terminals? While I was working on it, I realized that even if there is a stray resistance of megaohms, the buttons do not work properly. So the board has to be very very clean. I would expect problems on/near the buttons or the capacitors on the other side. In my case, the connectors were OK and luckily I did not have to replace them.

Looking for the answer in my case, I replaced both buttons with similar buttons, which turned out to be a bit more quiet. I would recommend this to everybody. Though I am not sure what the best replacement is, I just bought what was in stock locally.

ibu

  • Newbie
  • *
  • Posts: 3
  • Karma: +0/-0
Re: touchpad right button seems stuck
« Reply #18 on: November 21, 2017, 06:45:14 AM »
Earlier, the left button was acting as if it was the right button, and the right button didn't work.
This phenomenological behaviour could result from the right button being always pressed and the left button (when pressed) interrupting this, which leads to a new right-button-pressed event.

diegor

  • Newbie
  • *
  • Posts: 9
  • Karma: +2/-0
Re: touchpad right button seems stuck
« Reply #19 on: December 01, 2017, 09:50:48 PM »
Hi,

  some news hardware side. I've desoldered one of the two button, and the resistance measured on the other button was ok (open circuit). The funny things is that the resistance measured on the pad of the removed button was around 5k, even if the pcb was disconnected from everything.

  I've resoldered the two capacitors, and for some reason this fixed temporarily the problem. So I resoldered the button and the buttons now work fine... some time. Ok, most of the time they work, sometimes the phantom resistance reappeares, and the right button get stuck again.

  Have someone an idea of what is going on? Is there a more permanent fix?

Thanks in advance,
  Diego.

khumarahn

  • Jr. Member
  • **
  • Posts: 68
  • Karma: +6/-0
Re: touchpad right button seems stuck
« Reply #20 on: December 01, 2017, 11:50:50 PM »
@diegor, this is the same as my experience, only the resistance was 5K vs 11K.

That is a very simple circuit... Probably the phantom resistance is caused by the board not being entirely clean. After I cleaned it very thoroughly, I had no problems so far. I have a phantom F11 keyboard press occasionally though, but so rarely that I can't reliably reproduce or diagnose.

zinoviev

  • Newbie
  • *
  • Posts: 4
  • Karma: +0/-0
Re: touchpad right button seems stuck
« Reply #21 on: July 26, 2018, 09:16:39 PM »
Ok, guys. This thing happened to my laptop too, more than 6 months after I assembled it. :( Is there a spare part I can buy in order to fix my laptop? Maybe TERES-PCB3-TOUCH?