A capacity for quality

About eighteen months ago a higher-than-usual employment bonus allowed me to finally purchase a large, flat-screen television.  Had the bonus amount been even higher I would have gone with a beautiful 40 inch Samsung LCD but it was priced at four times what I wanted to spend.

So I settled on a very nice 42 inch Phillips plasma that had been refurbished, halving its cost to $1000 USD.  Buying it was a gamble, as it only came with a 90 day warranty instead of the one year coverage for a new TV.  The salesman wanted to add an extended warranty to the purchase but I declined.  He seemed to think I was an idiot but I had an advantage not shared by the typical TV buyer: a background in electronics.

My parents had bought me electronics experimentation kits before I was a teenager, and I took to them like a fish to water.  At around age 12 I even rebuilt my dad’s power saw (without his prior approval), replacing the electrical cord and armature brushes and providing the decades-old tool with new life.  Later, I was fortunate to be accepted into a cooperative education program with Texas Instruments that developed circuit card designers.

These experiences all proved useful, because after a year or so use our beloved TV stopped functioning.

As usual, Google was my friend.  A search on the symptoms quickly turned up the likely cause: blown capacitors.  I would have to operate on the beast.

I will credit Phillips with one thing: they take final assembly seriously.  Removing every screw to get at the power supply was an arduous task (more on that later).  By the time I exposed the guts I was one irritated TV surgeon.

The problem was easy enough to identify.  Two radial capacitors on the main board were puffing out on top, exposing a little electrolyte.  They were obviously no longer doing their job, and would need to be replaced.  Long story short, I purchased some replacements (going up a bit in capacity), desoldered the old ones and installed the new.  Not completely confident that I had identified everything, I tested it before reassembly and was relieved (make that ecstatic) when the picture returned, good as new… well, good as refurbished, anyway.

In retrospective analysis, I checked the expected life of the original capacitors against an estimated usage of the TV and realized they were very close to matching.  In other words, the manufacturer had done a really nice job of tying the normal warranty to the lifespan of the weakest link.  And all this time I had thought that to be an urban legend!

Amazingly enough, not long afterward, our GE Arctica refrigerator started acting up.  Once again Google helped identify the likely culprit: failed capacitors.

Within a week, our Xbox had gone kaput.  Can you guess what I found to be the most likely cause?

One connection between the three is my home AC power system.  We get a lot of prematurely-blown light bulbs so I am certain our power is “dirty”, i.e., the levels fluctuate beyond the acceptable thresholds (which can degrade capacitors).  I’ve been wanting to install a universal power conditioner for the entire house and this sure appears to provide justification.  I can’t install local conditioners everywhere, especially for lights!

But another common aspect is that none of these devices was designed for easy repair access.  Why did I have to remove the entire back of the TV to get at the power supply, a common failure-prone component?  Why was there no access panel?  I don’t expect that to be done for consumers, but what about the poor professional repairmen?  Isn’t their time valuable?

I can understand (to a point) the desire of manufacturers to limit appliance life, and thus the tendency to use discrete parts that will fail at or after that limit.  But at least combine that with a housing design that facilitates reasonable repair access.  That is a quality approach.  Doing otherwise is just another bad design factor that leads to high-end electronics being treated as disposable… and don’t our landfills have enough of that?

Warning: do NOT attempt the sort of repairs described without a good understanding of capacitors.  They can hold a charge long after the main power has been disconnected.

2 responses to “A capacity for quality

  1. allnameswereout

    Dependence.

    And keeping the stupid user doing stupid things.

    Therefore, the user has to come back to repair the device. Or rather, buy a new one.

    This should gain more attention for 2 reasons: 1) open source spirit or more vaguely: liberty/reliability 2) environment 3) longevity of product, brand.

    Nowadays, bad caps are less common. I tend to check my hardware if it has those old caps. But its difficult to do such at a store. And ofcourse, these caps break right after warranty…

  2. I’m getting the impression that in the past few years bad caps have become MORE common. I’ve read that difficulty procuring tantalum (main source is a wartorn country in Africa IIRC) is one of the reasons. But I’m betting the main driver is the never-ending race to the bottom of source pricing…

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