The Miracle of WD-40

Cringe. Please use contact cleaner for electronics (Servisol is a good brand). WD40 may well eat plastic & rubber seals (although nitrile rubber, eg. o-rings, should be safe). It's a light oil spray and water displacer. It's not a substitute for proper lubrication - it will wash grease & oil OUT of bearings for example. For brass hinges, locks etc. use graphite dust (soft pencil lead if you have nothing else, but graphite is cheap). Oil will attract dust and other crap and make the problem worse over time.

Don't do this.

If you've ever seen the mixing desk in a big recording studio or concert venue, you'll understand that maintaining buttons and knobs is something of a preoccupation for sound engineers.

The solvents in WD40 will clean switches quite effectively, but WD40 leaves behind a lubricating residue which isn't very conductive and will attract dirt. Using WD40 as a contact cleaner tends to be a vicious cycle - you end up using WD40 to remove the old WD40 gunk.

The best thing for the job is Caig Deoxit. It's not especially cheap, but neither is an iPhone 4. WD40 claims to do a million jobs, but Deoxit does only one - safely clean electrical contacts.

During my army service, I spent 3-4 years being an AN/TPQ-37 tech. Its a high-voltage, high power, immensely complex Radar. Even though it is such a beast, and could take a lot of mistreatment, we had one "do not use WD-40" rule tattooed into our brain. On the long run it always caused much more damage than help!

DO NOT USE WD-40 WITH ELECTRONICS.

We used to use Freon and silicon based lubricants - but I'm not sure these substances are legal anymore.

> the home button — the sole physical button on the device’s face

Isn't this a bit silly. The most expensive phone on the planet has one big button you barely use and they can't build it to last a year even after 4 iterations of (almost) the same design. Older cheap phones have plenty of tiny little keys, they last for years and years and those keys you use all the time because you don't have the touchscreen. Maybe that's the solution, press your home button more often.

It may work, but I wonder what else the WD-40 may be eating away. I'd probably try contact cleaner first.

WD-40 is crap.

It's marketed as a combination cleaner and lubricant, and it's bad at both of those.

If you need a cleaner, get a cleaner, if you need a lubricant get a lubricant. WD-40 will wreck anything you use it on unless it's something that's impossible to wreck.

I think it's most likely working as a lubricant. WD40 leaves a lubricating residue that in my experience works well on creaky door hinges. I never thought to use it on sticky buttons though!

You know what else fixes busted home buttons? AppleCare.

I don't actually understand why this worked, but it did.

Deoxit, which is carried by Radio Shack under their own label, will probably do a better job of dissolving grime and oxidation, and with less chance of unintentional destruction of innards.