I had this problem after I opened my case to fix a faulty vga cable! Basically I found that it has something to do with the ribbon cable that connects the touchscreen to the touchscreen controller. When i bend the cable it works, let it be straight it doesn't bend it not enough and I get erratic movements. Erratic being that the cursor would regularly jump the right hand side and be hidden there!
Anyone know where to get a touchscreen ribbon cable?, not for the display - that works fine, rather for connecting the touchcontroller to the screen. Could only find the 40pin display cable on
www.digitalww.com
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Argh just realised I have to replace the whole touchpanel to replace the little ribbon cable argh ! damn lilliputs! always breaking....
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Thanks.