Sounds like one side or corner of the touch element is being pinched, probably by the bezel.
I recently purchased this 8" unnamed touchscreen. (EDIT. I think the lcd is NiceView or atleast it's sold with that name in some stores. brand of the touch panel remains unknown)
Note! This is not meant to blacken the shop at issue, I just dont know the brand of the panel so it's just for reference. Their service was really good and fast
It worked well several hours but now it's started to live a life of its own . The pointer constantly jumps to the right edge of the screen, always to the same place even if I don't touch the screen at all. I've tried to recalibrate it several times without any luck.
I can see that the touch element is bit off to the right so it might be that the right frame of the panel is pressing the touch element or something. Can't see any dirt under the frame or anything.
Recalibaring the screen helps for few a minutes but then the problem comes back.
I think I saw some distortion in the "calibration net" when I was clearing the 25 point calibration data from the driver software. I don't know if that means a contact problem or a constant contact in some place.
Panel uses Worcol Touch drivers.
Has anyone else had similar problems and is there a solution for it or should I try to return the panel? (which isn't that easy as I purchased it from Germany and I live in Finland)
I'd really want to open the panel and check if problem would go away when frames are removed but that would void the warranty as there's a sticker between the two halves of the cover.
Yea I hoped it's that as I read several threads about similar problems and this was the usual presumed reason.
I however have loosened the screws on the problematic side and it doesn't seem to help. And when the problem isn't occuring and I try to press the right frame, I can't make the pointer to jump there like it does on its own. So I don't think it's becouse of tightness of the bezel.
Also, as there's that gasget between the element and bezel, I tried to push it deeper with a credit card. Seems to help a bit so I would guess it's either that or then just jammed area in the touch element and that area gets rubbed (which could help sometimes) while im stuffing the credit card over it.
Or in the worst case there's something wrong with the touch element controller
Ok well.. no matter how much I loosen / crank the bezel it still jumps to the edge(check the image ).
Quite opposite it seems to help if I press the frame
If its not the bezel, then maybe it a software issue. Use the calibration tool that should have come with the packaging.... Hopefully that helps.
Nirwana Project, the Android/Win 7 hybrid system!
1X Ainol Novo Flame Tab
3x Perixx Touchpads
3x 7 inch Screens
1X 7 inch motorized Screen
1x Win 7 PC
if the pointer is does not line up with where it is touched, then it is a software or calibration problem. but if it moves itself without you touching it then it's a hardware problem.
have you actually opened it up and adjusted the LCD panel mounting screws? or are you simply loosening the screws on the back of the plastic monitor housing?
loosening the screws on the plastic case/enclosure won't do any good. there are screws inside the enclosure that hold the LCD/touch panel in place (one of those screws may be too tight). if the panel is being forced against the bezel than you could try pressing on the side/corner that the pointer moves itself over to. this may push the panel far enough away from the bezel to sop the issue. if that doesn't fix it, then you'll have to open it up and adjust the panel retaining screws.
if you don't even know the brand name of the monitor, do you really need to worry about it's warranty? if you ever wanted to file a warranty claim on it, chances are you would have to pay to ship it overseas to Asia to have any work done on it (the shipping alone could cost more than the monitor itself ).
I'm not totally noob about these things and have opened LCDs before for DIY projector stuff but they where normal computer monitors so the structure is a bit different I think. In those the lcd element is just resting between front and back shell.
I'll try to pop the case open tonight. There's some clips holding it together which are always nice...
I'll post the results.
Thank you everyone for all the help so far
Maybe it's the ribbon off the touch panel or something around there shorting. Maybe to the metal of the LCD housing. Resistive touch is like a variable resistor across the screen, so to the left would measure the least resistance. Or in other words, shorting would make it think it's all the way to the left.
Oh wait, right edge? If it's all the way right, then it should be a break in the ribbon or or bad connection.
But like said, I'll try to pop it open tonight so that should rule out few possibilities.
PS. If it's really the faulty touch element, there isn't much to do, right?
Ok I performet autopsy for the poor bastard and unfortunately didn't find anything critical
I cleaned the edges of the lcd & touchpanel from top and under, centered the touch element as it was a bit off to the right, put it back together and tightened the panel holders just so that everything keeps in place.
Result? Same as before.
So I opened it again, checked, tested, opened again, checked... no luck.
It still can be the pressure somewhere as the this LCD unit really isn't made for touch function (there's parts of the plastic casing ripped of from here and there to get the touch element fitted). Also I didn't get the problem while testing the element while it was separated from the LCD, tho I did test it quite briefly only.
Anyhow well keep testing and reporting.
here's pictures to show position of the 4 clips (red arrows) so that if anyone would happen to open one of these.
Also added a cable tie (blue arrow) for the USB cable as it was on loose.