Touchscreen pointer jumps to right edge

**Bugbyte** · 03-11-2008, 01:52 PM

A wild shot in the dark, but is the ribbon cable from the touch panel to the touch controller plugged in upside down?

It wasn't clear in your post - you completely took the bezel off and tried it without anything touching the touch screen, right?

Seems a little fishy that it worked before you added it in and it doesn't now, but it isn't burned out or anything.

**sniiki** · 03-11-2008, 02:19 PM

Correction:
I didn't add the touch element, the panel was sold as a touchscreen. But you can clearly see that the touch element is added afterwards and not at the factory whoever made the screen itself.

And yes I've tried the touch screen sitting freely there. Don't think the cable is the problem and dont even know if it matters at all which way it's plugged as they're just resistors and before any calibration it acts all mixed up anyway.

And I found strange thing:
If I touch the screen VERY gently the pointer tries to jump to that place where it always stucks. Repeatedly touching the panel gently, the pointer will jump at the edge, always precisely at the same point.
Check the 5meg WMV video here:
http://users.evtek.fi/~anttimak/gara...ouchscreen.wmv

In the video the lcd is out of the casing and touch element sitting on it freely.

**Curiosity** · 03-11-2008, 03:03 PM

Looking at the video, I'd think it was another pointing device trying to take over. Got any other mice or touchpads hooked up?

**sniiki** · 03-11-2008, 03:09 PM

Originally Posted by Curiosity

Looking at the video, I'd think it was another pointing device trying to take over. Got any other mice or touchpads hooked up?

Yes mouse plugged in but I've ofcourse tested without it, it's not the cause either :|

EDIT. And I've also tested the touchpanel on another computer with same result.

**sniiki** · 03-12-2008, 03:52 AM

So following possibilities are ruled out:

-Pressure in wrong place (tested the touch element on its own)
-Computer specific reason (tested on a whole different setup)
-LCD panel's elektric interference (tested with the lcd power cable unplugged)
-Dirt (cleaned the element well)

That leaves me these?:

-intereference from outside source
-faulty touch element
-faulty touch element controller

This is again just a wild guess but are these things sensitive for outside interference? (dont think so). But last night when I moved the panel to other place and left it on running some visualization for hour or two, the problem didn't occur. (I know becouse the visualization is interrupted if mouse is clicked).

But the fact that the pointer jumps always to the excactly same position is referring to a faulty controller. This is just my opinion tho and maybe some else know better.

**FusionFanatic** · 03-12-2008, 12:04 PM

you can buy 7" touchpanel / controller kits on ebay for about $40 (+s/h). these have become very popular with ASUS EeePC users so they're easy to find, and much cheaper now.

good luck

**sniiki** · 03-12-2008, 12:06 PM

Continuing my monologue..

Here's another video clip (4megs) that shows that when the problem occurs and I press the frame quite hard near the point where the pointer jumps, it helps.

Maybe I could just shovel tons of crap between the frame and panel to get that pressure there constantly but I don't think that does any good for it in the long run neither it is an actual solution.

Damn this is getting quite annoying..

Anyone got a cheap 8" touch panel + controller for sale?

**sniiki** · 03-12-2008, 12:41 PM

Originally Posted by FusionFanatic

you can buy 7" touchpanel / controller kits on ebay for about $40 (+s/h). these have become very popular with ASUS EeePC users so they're easy to find, and much cheaper now.

good luck

Except that my screen is 8"

I'm realizing new stuff every minute..

Lead-in:
If you touch a touch panel from two different points at the same time, it guives a reading from the middle of those points.

So...
If the problem would be in the panel element and it would think there's something touching at the right edge and I then press the panel lets say from the opposite edge shouldn't it place the pointer in the middle of the screen? (yes it should)

BUT.. In my case when the pointer stucks to the edge, and I touch the panel anywhere, pointer jumps right where I touch. Then if I release my touch, pointer jumps back to the edge.

So what the hell does this mean or does it mean anything?
Controller unit is *****ed up?

The problem first occurred when I tried to do the 25point calibration for the first time. Prolly just coincidence tho..

But please share ANY ideas you have, coz I'm running out of my own.

Boy it would feel great if I'd just smash that thing with a hammer..

EDIT EDIT: Nevermind..

**Bugbyte** · 03-12-2008, 03:03 PM

Could it be a driver issue?

BTW, does the touch panel actually work when you touch it? I mean, pretty much where you put your finger is where the pointer goes, right? At least that's how it looks from the video. So the question is, can you control the computer by touch even though it jumps to that right hand side?

If it isn't a driver issue, it seems like a touch panel quality issue. It seems to fix itself if you press hard on the right, as if the layers are delaminated or not working properly.

**sniiki** · 03-12-2008, 04:42 PM

Have tried several drivers, didn't seem to help.

Yes, the panel works but when the pointer decides to jump to the edge, it also toggles the left mouse button, so when I then touch some other part of the screen I get that dash-line square thingie on windows desktop. Then I usually get mad and whack the poor panel a bit untill it stops scewing around meaning the pointer doesnt automatically jump to the edge anymore.

(Lcd panel it self starts to give some sings that I've been too rough for it as there was a connection problem and it gave one vertical blue line for me

Not permanent tho fortunately

)

Now I tried one more thing, changed drivers again and put some more insulant between the metallic lcd frame and touch panel. I should not say this but.. seems to work again fine.

btw. 8" panel + controller is ~57$ incl. shipping from Hong Kong (ebay)