4 minute read

I travel a lot.  On the road, I depend upon wireless connectivity everywhere I go.  Recently, I got fed up with the lack of dependable Wifi service (it is horrible at ATL for example), so I purchased a Laptop Connect card. EVDO, 2xG, 3G… if there’s service, this card will pick it up.

This story has four parts: The Card Problem, The Apple Store Experience, the Analysis and The Latch Fix.  If you are only interested in the fix, skip down to that part.

The Card Problem

I was initially very pleased with the card’s performance on my Macbook Pro, but almost immediately the card become difficult to seat in the Expresscard slot.  It would take several attempts before the latch “caught” the card.  This was inconvenient, but not a deal breaker.

But the card became *more* difficult to seat, and in fact started randomly popping out of the slot.  By “popping out” I mean exactly that – the spring inside the Expresscard cage’s latch assembly would let go of the card, forcing the backstop in the cage to forcefully eject the card.

Um, not good.  I dealt with this increasingly more severe issue the past two weeks, and by Wednesday (two days ago), I could effectively no longer use the card.  I went online & made an appointment at the Apple Store Aspen Grove for this morning – the only business day I have available to get this fixed in the next three weeks.  Did I mention I travel a lot?

The Apple Store Experience

I got to the Apple store & they said they couldn’t fix it on the spot. They’d need 2 or 3 days minimum, and maybe more if they had to order parts.  I explained that wasn’t possible because of my travel schedule – I really needed it fixed today.  The guy told me that if I was a Pro Care member, they would put me at the front of the repair line.  I was too pissed to buy the Pro Care (he didn’t offer that anyway), and proceeded to tell the guy I would fix it myself.  I briefly mentioned that all the other gear I was ready you buy during that visit (about $1000 worth), would not be purchased.

While we were talking, he did remove & clean the springs under the space bar, resolving a maddening squeak that I understand many MBP owners have.  So kudos for that, Apple Store dude.

The Analysis

Once I got back home, I was determined to fix this.  Years ago, I repaired computers and still have my professional toolbox.  Using a plastic probe & my headlamp, I opened the Expresscard slot door & assessed the card-cage assembly.  I could see a set of rails (one on each side) along which the card traveled (guided) as it was inserted into the slot.  I also saw the likely culprit of the issue: the spring-loaded latch on the right side of the cage.

It looked like the spring was slightly askew relative to the otherwise perpendicular orientation of the rest of the cage & rail parts.  This convinced me that the spring was slightly bent, and thus was never fully compressing (loading) behind the card as it was inserted.  This changed the length of travel of the spring as it compressed, which caused the back-stop to only slightly be touched at insertion. 

This, in turn, meant that the latch would either not engage the back-stop at all (as evidenced by the multiple failed inserts), or the latch would only barely “grab” the back-stop… and after some brief period, the latch would “let go” because the spring tension was pulling it across the edge or side.

The Latch Fix

Now that I was sure the issue was purely mechanical, and realizing that I really didn’t want to disassemble my MBP, I considered the obvious: physics.

 A basic physical property is at work in securing the card in place: spring potential energy.  I speculated that gravity was compounding the issue, by pulling the deformed spring out of square with the backstop just enough that it would no longer positively engage the latch.

If I could defeat gravity, I may be able to resolve the issue.  Fortunately, I didn’t need a huge laboratory or special ray guns.  I only needed to turn the MBP upside down, laying it flat on my desk.  Gravity was now working to force the spring back into its correct position.  At this point, I turned the EVDO card upside down and inserted it into the Expresscard slot. 

As expected, it immediately latched.  I then carefully turned the MBP rightside up, powered it up normally & was able to connect flawlessly.  It has been inserted & running for about an hour now; yesterday the card wouldn’t stay inserted (when I could *get* it inserted) for more than one minute.

This worked for me and may work for you too.

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