[NTLK] Newton touchscreen not responding
simonepsp at gmail.com
Thu Dec 25 15:56:19 EST 2014
thanks for your analysis Frank :)
I took my multimeter and I made some measures using my multimeter (hope I
didn't made mistakes) :
WITHOUT TOUCHING TOUCHSCREEN:
- Contact 1 - 3 : 528 Ohm
- Contact 2 - 4 : 404 Ohm
- Contact 1 - 2: /
- Contact 3 - 4: /
TAPPING THE SCREEN:
- Contact 1 - 2 :
A) 890 Ohm
B) 710 Ohm
C) 1200 Ohm
D) 860-900 Ohm
- Contact 3 - 4 :
A) 794 Ohm
B) 1158 Ohm
C) 541 Ohm
D) 873 Ohm
Results are very different from yours. Tell me what you think about :(
Here's the photos of interconnect port connector you asked me:
Thanks for your help.
2014-12-25 0:31 GMT+01:00 Frank Gruendel <newtontalk at pda-soft.de>:
> I will send further communciation only to NewtonTalk since it might benefit
> others. Moreover, it'll be easier for both of us.
> I assume that you have noticed that one of the ribbon cable traces is
> somewhat bent out of the way. Since in the first set of pictures you
> published this was not so, this is most likely not the reason for your
> problem, but make sure to realign it before you try your luck again.
> I have just uploaded some technical details of the 2x00 digitizer here:
> Provided you have a multimeter that can measure resistance, this will help
> you figuring out what is wrong with your digitizer.
> Some words of explanation:
> The rectangular thingie on the left-hand side is the digitizer. The drawing
> on the right-hand side is the end of the ribbon cable.
> Contacts 1 and 2 sense the horizontal position, contacts 3 and 4 the
> vertical position.
> If the touchscreen isn't touched by anything, you should measure
> approximately 575 Ohm across contacts 1 and 2 and approximately 435 Ohm
> across contacts 3 and 4. 1/2 and 3/4 must not be connected by anything. If
> you measure any resistance between the two pairs, there's a short somewhere
> that shouldn't be there.
> If you tap in the middle of the top, left-hand, bottom and right-hand
> you should measure approximately what I wrote next to the little dots. If
> you tap in the corners (A, B, C, D), you should measure the values I wrote
> at the top.
> Please let us know your findings.
> I would also like a close-up image of the interconnect port connector. This
> will most likely not be the cause of your digitizer problem, but as I said
> in one of my previous mails, I am under the impression that before long it
> will tear off since some soldering joints are already broken.
> Good luck
> -- Newton software and hardware at http://www.pda-soft.de
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