Q: TrackPad won't turn on after batteries were changed.

Did the aluminum foil, but it did not work.  I tried shaking the trackpad, nothing. 

In desperation, I found a solution:  Hit the track pad 3-4 times vigorously in the upper middle section of your trackpad near the battery and actual track area with your fingers. 

On very rare occasions have I found violence to amount to anything.... this did!

I've just had the same issue. After not using the magic pad for a while i put in some new batteries and nothing......tried a shake tried a tap and tried the bouncing the batteries thing but thst did nothing. so i wrapped the positive end of the first battery in foil and hey presto green light straight away. the connection at must be tempremental in the pad for the looks of this thread

This also worked for me, the spring must loose it's spring and the contact is lost.  Thanks for the great tip!

I can't get the battery compartment open on my track pad.  The screw-out cap won't budge.  I even bent a quarter trying to unscrew the cap.

Anyone have any suggestions? 

Just bought Trackpad...right out of the box i can't turn it on.  Came with batteries installed.  Tried to push the on/off button but no click like there is with the bluetooth keyboard.  I suppose it is defecfective.  Really looking forward to going back to the store.

Is there something I am missing?

Aluminum foil and pressing on the spring definitely worked!

I had this problem and I used a pencil eraser to rub the battery compartment contacts at both ends in order to clean them.  It fixed the problem and the trackpad powered right up.

I have this problem also, almost always I replace the bateries of the MTP.

I usually solve it deactivating and reactivating the bluetooth.

Or sometimes I had to restart.

Just experienced the same issue where the trackpad only powered on for a moment (under a second) after replacing the batteries. After trying three sets I broke out the voltmeter to see if battery voltage might have something to do with it, sure enough two pair only registered 1.3v, one battery was completely dead. The fix was a fourth set of batteries, both putting out over 1.5v. If you don't have a volt meter, I'd try buying a new pack of batteries and testing different combinatioins until it powers on.

In my case the Magic Trackpad required batteries putting out 1.5v to startup. Hope this helps someone.

Thanks...turned out I had a defective pad.  Exchanged it and it is working fine now.  Not sold on it as my sole tracking device but provides more flexibility when used with a standard mouse.

Just hit it with your finger in the place the two batteries are connected! You should see the green light right away!

And that indicates the batteries are ill-fitting.    They are either of low grade manufacture from dime a dozen stores or the contact points are weakening.

With the former, they may not be the exact AA size.

With the latter being the case, go for an exchange if within warranty or pack the points with a folded piece of tin foil.

I was having the same issues; received a message on the computer that my trackpad batteries are low.  So I put in two new Energizer 1.5v AA batteries.  This is the same exact brand as what came in the trackpad, however those that came in it say "Advanced" and what I was using do not.  When I pushed the on/off button, I got a split second green light (which I know it does not stay lit constantly) and a window came up on the computer saying it was trying to find the device...to no success even after removing an re-installing the batteries multiple times.  I finally put the old batteries back in a viola....it is working.  But what a PIA this will be if it won't recognize other batteries.  Because it worked after I put those original batteries back in only leads me to believe I am going to have to use the exact same ones in replacement.  ??

You are a frigging genius. This worked great.

The threads of the Trackpad body were dirty on mine, and cleaning them resolved the issue.