[rant on]
I'm getting really frustrated with these. I've just gone through my third one in less than three years. Each one died the same way. The tiny springs behind the pins corrode because of the salt in the air here (I live a few feet from the sea). The pins then no longer make a snug connection. This causes heat. heat kills.

Don't get me wrong, they are a fantastic idea, and have saved my notebook from drops several times over, but I wish there was something they could do to keep those springs in good shape.

At the very least they could sell the MagSafe connector for the end of the cable. I'd happily pay $10 for the connector and replace it myself rather than having to shell out $45-$80 (retail) for a new power adapter every time. I've got three perfectly good ones with ruined tips sitting in a box.
[/rant off]

Have you tried forcing some silicone grease into the new connector?

Also, by all means send one back to apple with an explanation and a request for a replacement.

Yeah, I should at least spray WD-40 into the connectors on a regular basis. It just gets hard to remember and I don't have it around a lot of times.

Perhaps when I get back to the US, I'll take all 3 or 4 of my bad supplies into apple and let them know that this is a reproducible problem, not just an isolated occurrence. It even happens on schedule every 10-11 months.

You shouldn't have to put WD-40 or similar on that often if you do that. Maybe even once for life would be enough if the springs are somewhat protected.

No! Not WD40.

The volatiles in that crap evaporate, leaving behind a sticky varnish. It's cure worse than the problem.

Also if any are the inline connector style, and have frayed at the connector, there is a replacement program going on. The new PS have rt. angle connectors.

WD-40 is not the answer. It displaces moisture (the primary/original purpose of the product) but does not provide a lasting protection. I hesitate to recommend a specific product here, but I can relay some that may lead you in a useful direction.

Dielectric grease is often used around and inside electrical connectors that need protection from water and corrosion. Often applied at the factory to automotive and marine electrical connectors. The type I typically use is a clear gel form, but I think it also exists in liquid and/or aerosol forms.

In regions where salt is applied to winter roads, spraying the undersides and metal cavities of cars with a protective oily spray is common practice. Two brand names that are common in my area are Rust Ceck and Krown. Both products normally applied at automotive shops, but aerosol spray cans are also sold for consumer use. I have applied Rust Check spray to many things, from door lock cylinders to the bolts on outside equipment.

In general these anti-rust products are also safe to use in and on electrical connections. On rare occasions the oil has reacted with the plastic wire insulation, causing it to soften or swell. Depends on the particular insulation material involved. The oil does not conduct electricity, but it does creep across surfaces (as part of its anti-rust properties) so whatever you apply it to will be oily to the touch. Frequent wiping off of the outside surfaces eventually minimizes the mess.

I imagine the spring cavity inside the MagSafe connector is tiny, so a fraction of a droplet of protectant would probably be enough to soak the tiny steel springs and protect them. Whether you can effectively do so without creating a messy connector during future use I could not say.

If indeed you can convince Apple to replace several or all of your failed power adapters with new might be the most effective 'fix'.

There was a time when third party companies (well, at least one ) would sell repaired and refurbished Apple power adapters. I bought at least one which came with a brand new connector. Indeed, their web site showed examples of frayed cable ends and damaged connectors. This tells me they had access to replacement connectors. I don't know which companies still sell refurbished 'genuine Apple' power adapters. Lots of knock-off Apple fake products around.

A quick Google search turned up images of MagSafe connectors with attached cables (sans power supply).

Vaseline ("petroleum jelly").
If you must use a liquid, then "sewing machine oil",
or any similar "sticky" oil.

Cheers

Memory of this post got me some brownie points with SWMBO, last night. Her laptop had refused to charge all day. I came home, and pushed all the little pins in the connector a few times to release any sticking springs, and all of a sudden her Mac would charge again.

So... thanks!

Use those points up quickly, lest they 'expire'.

In other news, I'm on my fifth now (and hopefully last since I'll be back in the US in a month).

At least I can get them on Amazon for $37 now instead of paying $80 in the old days.

Reviews on Amazon at that product page vary widely but overall seem rather negative.

Is there a specific Amazon seller that you prefer?

$31.30 (delivered) at dx.com.

I've just purchased using the link above. Looking back at my orders, they've come from two different sellers. I always use sellers that offer "fulfilled by Amazon" and rarely have a problem.

Note that these do not come with the 6ft three prong extension like the retail version. I've always been replacing an old one, so I just pull it off the old one and put it on the new one.

Those (if the picture is accurate) are the first generation 85W power adapters Apple shipped with MagSafe. They should work fine, though keep in mind they do have a defect in that the cord can fray and cause a hazard. The recall on them is still active, but it requires the cord to have begun to fray.

http://support.apple.com/kb/TS4127