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.