Q: IMAC

Cleaning your Apple products - Apple Support

Have you bought a new Trackpad or is this the original one?

I suggest you take it in for testing and diagnosis. There are many things that could cause what you describe.

Also, five years is a long time for technology devices to perform without problems.

Barry

Have you by any chance upgraded your iMac to the latest 10.11   El Capitan.   If you have done this, that is the reason your trackpad is playing up.   These new OSs require a new version of trackpad to be fully functional.  The old trackpad may or may not partially work.

But don't buy the new trackpad if you haven't upgraded.  That would not work properly on an older OS.

Sorry, wrongly addressed.

Did you make any progress with this matter; had you tried to upgrade to El Capitan?

Hi Seventy one, I'm not so sure you are correct on the older track pad not working with the newer OS. I have a mid-2010 i-Mac and am running OS X 10.11.6 and my 2010 vintage track pad works fine.

I'm saying that the entire range of settings may not function.  It may be that your requirements with your vintage trackpad do not include all the options.  The key point is that the New magic trackpad 2 is meant for El Capitan and later OS's such as Sierra, to come over the next month or two.  Try to be prepared for diminishing facilities with your current track pad with the forthcoming upgrades.

Hi Seventy One... Got it. Thanks for the clarification. I didn't realize there might be new / different capabilities in the new generation of track pads & mice. I'll have to watch for them.