I am the (french) new owner of a "A1181-Macbook"based Modbook (early 2009). I was first very satisfied with my new Toy. Unfortunately I noticed very quickly that the cursor began to jump to the upper left corner (" the cursor goes to the upper left and ‘freaks out’ "). That occurred more and more often, especially with Photoshop (processor heavy software?). Every now and then, I couldn´t use it anymore.

Eventually the problem disappeared... As the screen went dark! No backlight anymore.

As the Warranty expired, I decided to dismantled my Modbook in order to reached the inverter board.

Big surprise when I opened it. The (many) thin cables between the two halves of the modbook were badly squezzed and pinched (I made photos of that and I can post them if required). These cables are gathered at the upper left corner of the modbook on its working position.

In order to check them out, I have put the isolating coat away form the cables where they seemed to be broken. I recoated them with dicker isolating tape after the check up, taped them together and arranged them in a way that they could not interfere with the edges of the two halves.

And guess what? After putting everything back together, The dreaded jumping cursor completly disappeared form my modbook. Not even one time. I couldn´t believe it.

These cables may have caused magnetic fields and interferences with the Tablet at this place. Sounds like an explanation?

Absolutely! I've had an intermittent "hot spot" that shows up on screen near the upper left corner of my Modbook's screen but never the jumping cursor. I think nervouschimp confirmed some wire bundling at this location. Post some picks so others can see how to undertake this fix.

Gallery of photos from the internal wire bundling at the upper-left corner of the modbook.
From outside:
   
From inside
   
Where the cables were pinched:
   
The result:
   
Time to close it up. Let's be carefull this time:
   
Hopefully these images will be helpfull!

This post was last modified: 01-12-2010 12:34 AM by Alex.

Nice. Keep us posted as to whether this continues to function as you push your modbook to perform more strenuous tasks.

This post was last modified: 01-12-2010 03:55 PM by pod.

So far so good. I worked all day long yesterday, no djc! This never happened before! My work on the wiring at the upper-left corner of the modbook hat an effect on it!

The "uncoating" and repairing of the wire has caused the shortening of the wire bundling at the upper-left corner of the modbook. As Magnetic field are caused by cylindrical length of wire (solenoid), I may have prevented it by laying them back straight, with dicker isolating coating.

I cannot test it anymore but, by djc, one may try to unplugged the power supply and dimm the screen in order to lower the current in the wires at this spot.That would confirm this explanation....

If the djc appears again, I will post it. If not, "pas de nouvelles, bonnes nouvelles!".

I have to dismantle the modbook shortly (inverter Board to replace). If more photos of the internal wiring are needed, let me know shortly!

Your description of the bundled wires acting as a solenoid makes pretty good sense. What is "dicker isolating coating"?

Sorry for my poor english, and moreover I mix it with my german.
I meant : the wire were better insulated, with thicker rubber tape. Is that correct?

More photos...
I have dismantled my Modbook again in order to replace the inverter board. I took pictures again of the internal wiring of the upper left Corner of the Computer. All the wires are free in an original Modbook. there are tied up together in mine. In order to prevent any magnetic effect on the tablet due to a risky solenoid wiring underneath .
           

Yes and...

Thanks!

Merci beaucoup!

Danke schön!

Alex -

Thanks so much for your post!
I was wondering if you have noticed any return of the jumping cursor on your ModBook since you fixed it with the insulation tape.

Has the tape caused any other issues with the ModBook - causing overheating or anything?

Thanks again for taking the time to post detailed photo's!