Editing Touchpad (section)

==Gallery==
<gallery widths=250 heights=187>
File:Trackpad_right_hand.jpg | A person using a trackpad.
File:Worn_trackpad.jpg       | A trackpad showing signs of wear from heavy use.
</gallery>

===Dell Inspiron 7720===
The following Alps 56AAA2266A touchpad was retrieved from a dead Dell Inspiron 7720 computer. The trackpad takes the form of a PCB, with two connectors: one cable (pictured) provides a data connection to the computer, and the other connects to a separate PCB bearing the buttons. An area of exposed copper provides a surface onto to which to affix a flat, braided metal grounding strip (poor grounding can cause wildly spurious sensing).

The touchpad is a plain PCB; the surface on which the user's finger is placed, is part of the palmrest, and in this instance the PCB was glued onto the palmrest. The trackpad was levered out carefully with a screwdriver and the glue removed; this has left gouging in the underside of the plastic cover in the palmrest.

The matrix is diagonal, with alternating row widths and column heights. Vias carry the current from the control side to the sense side; there are also a row of unused vias with the holes absent. Carbon bridges join the matrix together.

<gallery widths=250 heights=187>
File:Dell Inspiron 7720 -- trackpad fitted.jpg         | Touchpad fitted
File:Dell Inspiron 7720 -- trackpad space.jpg          | Touchpad removed
File:Dell Inspiron 7720 -- Alps 56AAA2266A, top.jpg    | PCB, top
File:Dell Inspiron 7720 -- Alps 56AAA2266A, bottom.jpg | PCB, bottom
</gallery>

[[Category:Pointing device types]]
[[Category:Touch device types]]