DS Lite touchscreen issue - how to calibrate 'pressed' voltage level?

Discussion in 'NDS - Console and Game Discussions' started by oneWonders, Jul 17, 2017.

  1. oneWonders

    oneWonders Member

    Apr 28, 2017
    I have a strange issue with my touchscreen where when you press on the screen it will rapidly press and unpress in the location you are touching.

    The positioning of touch points is fine, it's just that it rapidly touches and releases which as you can imagine causes massive problems in some games but not others.
    I genuinely don't think the actual touchscreen hardware is damaged as the positioning is fine and it also hasn't ever been abused.

    Is there a firmware setting that controls the sensitivity of when the screen thinks that it has been "pressed"? As maybe this is the issue? I read someone mention about this somewhere and that they sent it back to Nintendo who reset it and it was fine.
    Or is it likely to be bad contacts on the touchscreen connector?

    I tried taking the battery out so that it reset itself but that didn't seem to help.

    One thing I have noticed is that using the non-standard charger that I have causes the issue even on normally functional DS Lites.
    The DS Lite i have is actually japanese which is why I have a 3rd party charger (I imagine plugging the japanese charger into UK sockets would blow it doesn't mention being rated for 240V?)
    What happens is that when the 3rd party charger is plugged into a working DS Lite then it causes these same issues and then when you unplug the charger and run on battery (or use the official uk charger) then the touchscreen goes back to normal.
    It's very strange - could it be some kind of weird interference? I wonder whether using such a charger for a long period of time caused the calibration of what the screen considers as "pressed" to go out of whack.

    It doesn't affect the whole screen usually, with parts of it being okay.

    Any thoughts or ideas?
  2. Khadir

    Khadir Newbie

    Jul 19, 2017
    United States
    Astoria, New York
    If you mean the magnitude of which the NDS recognizes the touch (as the NDS is dated, I wouldn't want to use the term "haptic feedback" but that is the first thing that comes to mind): that would seem to be root code and thus not something easily modifiable. Despite the idea that this problem may not lie on a physical setting, you may want to consider that it does. Using a third party charger leads to a high gradient (difference) in voltage output per time as they lack voltage regulators. This can cause electrochemical oxidation, causing your battery to swell up.

    Given that you browse these forums, there is a high chance you've seen a battery that looks like it's about to burst, or a swelled up battery on some old laptop or piece of tech. If you haven't, google image search: "Swelled up battery" works too!

    It's possible that the battery has swelled up (even by a millimeter or two, something unnoticeable) causing pressure on the display, but not so much that it touches the plastic screen of the DS and registers a touch randomly. If so, when you touch it with the stylus, it could have a longer period of contact with the plastic screen due to that pressure, causing an extended period of touch registration.

    (Note: On top of the display, is a thin piece of plastic. You tap on that piece of plastic with the stylus when you use the NDS).

    Or I could just be dead wrong, who knows :rofl2:

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    Last edited by Khadir, Jul 19, 2017
  3. oneWonders

    oneWonders Member

    Apr 28, 2017
    Thanks for replying!

    The battery hasn't swelled up - I remember even temporarily swapping it with the one from the working ds lite and it still had the same issue.

    Also i'm not sure you understand the issue fully, i probably didn't explain it well enough.

    When you press on the screen (even in one spot, for example), what will happen is that the touchscreen will register as rapidly pressing and unpressing at the point where you are pressing with your stylus.

    It doesn't press randomly or keep pressing when you stop touching the screen.

    It's like the voltage level required when you press down on the screen is only barely being met and due to noise it fluctuates above and below what the ds considers a suitable 'pressed' value.
  4. migles

    migles All my gbatemp friends are now mods, except for me

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    Sep 19, 2013
    in the battery compartment you find 2 voltage regulators.
    but i do think theese are for the screens itself, not the touch panel...
    they are marker IIRC by VL1 and VL2
    be very carefull with them, they seem very sensitive, and can fuck up the screens

    this is the only thing i am aware about..

    — Posts automatically merged - Please don't double post! —

    there is no firmware setting.

    i think you probably answered it? if that issue happens in other ds by using that charger i am pretty sure it's the charger.
    get a normal charger. i have an european offical one, it's rated for 230 ONLY, doesn't say 110-230... so i guess the japanese one, is to be used in japan only as well
  5. oneWonders

    oneWonders Member

    Apr 28, 2017
    Well the problem is with this dslite, it permanently behaves like this now - even if you use an official charger or just run on battery.
    I was just giving the example that while the charger is plugged into another working ds lite it also exhibits this behaviour but goes back to normal when unplugged or using an official charger.
  6. oneWonders

    oneWonders Member

    Apr 28, 2017
    Any ideas? Or does anyone know anywhere else that I can ask?