Erratic cursor movement on the Samsung Moment

I’ve had my Samsung Moment a while now and one of the things I noticed was that in intense sunlight, the cursor would begin moving erratically out of control. Only in the most intense sunlight, and only under the right angle and conditions, but it would happen suddenly and because the cursor would continue to scroll in one direction keyboard input became effectively useless.

Since the Moment only has 1 input device that is affected by light intensity (the optical trackpad) I knew it would be a fairly simple fix. I confirmed my suspicion by placing my finger over the trackpad another time when the cursor was going bonkers, and it stopped immediately. I figured the intense light must be “blinding” the sensor and causing it to report movement against the minor changes in light intensity.

I figured returning the unit would be pointless since (1) I knew it would be difficult (if not impossible) to replicate it in a lab, and (2) I didn’t know if the next unit would have the same issue. So I set out a way to “fix” it.

Knowing that the optical trackpad was responsible for the erratic pointer movement, and that I didn’t use it enough to miss it, I set on finding a way to disable it. My first thought was to disassemble the phone and unplug the cable, but the fact that was a lot of work on my relatively new device, and that it might be part of the LCD assembly discouraged me from going that route.

My ultimate solution was simple enough: To cover the trackpad with a sticker and use an x-acto knife to cut it down to just the size of the trackpad.

My finished work:

If you’re going to try this yourself, my advice would be to reduce the sticker over several passes. Go around the “lines” in the case itself first to get the sticker small enough to only slightly larger than the trackpad. Then carefully go along the inner edge of the trackpad itself. Use a gentle hand and don’t be afraid to start over.The last thing you want to do is gouge your device.

The end result is no more “blinding” of the sensor by the sunlight. My cursor is “sane” again and I can still “click” the trackpad. No more scrolling though, but that’s an acceptable trade-off.