A Satisfying Weekend...

Our living room opens onto our patio through a sliding glass door, or at least it used to.  Our old door was an old-fashioned glass door made of many individual panes of glass all held together by a wooden frame.  Our dogs, through years of scratching at the door, had worn through one of the wooden frame pieces, and burst one pane of glass right out of the door.  I made some emergency repairs with epoxy on the day it happened – and then we bought a replacement door.  This time it's a conventional hinged door (not sliding), and with a steel frame.  The dogs will not hurt this one!

I guessed that replacing the door would take a couple of days for Debbie and I, and that we might need some help (the new door was heavy!).  So we lined up Jimmy B. (our friend and neighbor) for some help, and this weekend was scheduled.

Saturday we “demoed” (demolished) the old door first.  This ended up taking most of the day, and involved one major frustration.  Once we got the old door physically out of the wall, we did a trial fit of the new door.  It's outside trim was larger than the hole left by the old door – we needed to cut between a half inch and an inch of stucco all the way around the door.  That's about 22 feet of stucco to cut.  Some of you may not be familiar with stucco – it's basically a half to three-quarters of an inch of concrete slapped onto a wire mesh made of high tensile strength steel wire. 

I'd never cut stucco before, so I did some Googling and found lots of advice.  All of it recommended using a diamond saw blade on a 7" angle grinder.  Naturally, this is a tool I didn't own (doesn't it always work that way?).  So down to Lowe's I went (an hour's round trip) to buy an angle grinder and a 7" serrated diamond blade.  I got back home, unpacked the new tool – and promptly discovered that there was no way the blade would fit on the angle grinder.  Argh!  Back down to Lowe's I went, whereupon I met up with a very helpful tools guy.  It seems that California passed a law that went into effect on January 1 of this year, outlawing angle grinders that would accept a saw blade.  Anywhere else in the U.S. I could still buy one, but not here.  Double argh!  Damn the nanny state!  However, the tool guy did make one very helpful suggestion: the diamond blade would do the same job on a worm-drive circular saw – and that's a tool I happened to own.  So back home I went, and drug out the huge, heavy, worm-drive circular saw.  I fitted the diamond blade and went to work cutting stucco.  This worked extremely well, but generated huge quantities of fine white dust.  We had to seal up the house with plastic to keep the dust out, and even so some leaked in.

Once we got the hole cut, the more satisfying work began.  On Saturday evening we got the door in place, tacked it in (just enough to keep it from falling out).  On Sunday, we adjusted it for level and squareness, screwed it into the frame very securely, then filled the voids all around with construction foam (wonderful stuff!).  Then came the really fun part, the part that involved some craftsmanship: we formed a concrete support for the sill, patched the stucco all around the outside of the frame, and then re-grouted the gap between the inside sill and the entranceway tile.  That took all day, but when we were done it actually looked like a real door.  Now the only thing we have left to do is to trim off the construction foam that expanded outside the frame, and then mount some trim boards around the inside of the frame.  Easy stuff! 

The work we did on Sunday was strangely satisfying to me, in the same way that writing some challenging software is satisfying.  It's something about the need to engage my brain, the pure craftsmanship involved in building something, and obtaining pleasing results.  All of that put together is a reliable way for me to have a good day.

Plus we have a new door!

A Satisfying Repair...

A couple of months ago, I bought a Das Keyboard (at right) for use at home.  It has the mechanical switches whose “feel” I've long missed.  My typing isn't as fast or as accurate on the modern keyboards with (usually) rubber dome switches.  So I splurged a bit (these things are expensive!).  Within a couple of weeks, the constrast between my keyboard at work and my keyboard at home was unliveable, so I bought one for use at work as well.  I love my Das Keyboards!

But my keyboard at home developed a truly obnoxious problem.  The left-arrow and up-arrow keys (just to the right of the right shift key) started working intermittently.  For a while, they'd work only if the keyboard was tilted toward me (with the top edge higher than the low edge).  Then they stopped working altogether.

I contacted support at Das Keyboard, and very quickly they said they'd never seen this particular problem before, and offered to exchange the keyboard.  That's entirely appropriate support, for which they should be lauded – but it wasn't what I wanted.  Now that I've grown so attached to my Das Keyboards, I was loathe to have to use something else for the few weeks it would take to send my old keyboard back and get a new one in return.

So I decided to try to fix it myself.  I've designed switch-based keyboards, so I'm very familiar with how they work.  There's really not much to go wrong in such a keyboard – it's just switches, diodes, and printed circuit board – any of which I ought to be able to fix.  So to work I went.

The first step turned out to be the most challenging: getting the danged thing open!  I'm not sure I would ever have figured it out if it weren't for this lovely post (thank you, Geoff Breach!).  Thanks to his precise directions, I was able to open my Das Keyboard, and without breaking anything.

The next step was to study the situation.  I had a good clue (what every debugger wants most!): two keys simultaneously failed in the same exact way.  This means it was extremely unlikely to be a key switch problem, as the chance for two of them to malfunction identically was vanishingly small.  It had to be something in common between the two, and that could only be a diode or a printed circuit trace.  It took just a minute or so to figure it out.  In the photo at right (click to enlarge), you can see what I discovered.  The two orange ovals at right show one of the terminals on each of the up-arrow and left-arrow switches: they are connected.  A long skinny trace (highlighted by the arrows) connects them to one terminal on the enter key switch.  The enter key always worked fine.  The problem had to be an intermittent break in that skinny trace connecting them.

A little work with my DVM quickly confirmed this hypothesis.  While measuring the resistance between the enter key's terminal and the up-arrow key's terminal, I twisted and prodded the circuit board.  Sure enough, the resistance varied all over the place, from infinity to near zero ohms.  Somewhere on that trace there must be a hairline crack (so thin I couldn't spot it, even with a magnifier).  So I tried a brute-force repair: I soldered a piece of hook-up wire between the two terminals.  Voila! I reassembled it all without difficulty, and now my Das Keyboard is now as good as new.

I haven't the words to describe how satisfying it was to be able to troubleshoot and fix this.  Silly, I know, but true nonetheless.  Note that in the process of repairing it myself, I violated the terms of my warranty, so now my keyboard is truly mine.  I'm sure the Das Keyboard folks would sternly disapprove.  I'll tell them anyway, as they may be interested to know of a potential manufacturing quality issue...