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.. fix the DVD player (bulgy caps)

January 19, 2012

Last year, One Guy’s TV stopped working. After much to-ing and fro-ing, it was determined that yes, it was still under warranty, at just over 2 years old. The power supply board had a problem, and Samsung organised a replacement board with the local authorised repairer.

A few weeks ago, I repaired our DVD + Hard Drive Recorder. Today I repaired our older DVD player.

The short story

A lot of electronic equipment and appliances have an expected lifetime of only a few years, due to a particular inexpensive component, which can often be replaced.

The technical story

The capacitor is a basic and very common electronic component. Capacitors come in a variety of constructions, but those with greatest capacity are mostly cylinders of aluminium foil with an electrolyte between the layers. For a while, the preferred electrolyte was polychlorinated biphenyl (PCB), which worked well, but was highly carcinogenic. Not good for workers in component factories, nor anyone else who came in contact with the internals of a capacitor.  Now a much safer chemistry is used, but it’s nowhere near as durable.

Broad applications

My employer makes a habit of requiring a 3 year warranty with all new computers bought.  There was one model, of which we probably had 50 PCs, where every single one of them developed a hardware fault within the warranty period. They all had a telltale sign: “bulgy caps”. The tops of the electrolytic capacitors were bulging, indicating the capacitor was coming apart.

This was the problem with our TV.

Our DVD+HDD recorder recently failed. Occasionally it had taken a while to start up, but this became more frequent until it just gave up. It was out of warranty, so I took a look. Sure enough, two bulgy caps on the power supply board. So, I went shopping online for replacements.  RS-Online have quite a range, and make it easy to compare specifications. Looking through the options, I noted something interesting: even the best, most expensive parts had a rated lifetime of 10,000 hours.  If an appliance is left on all the time, that’s not much more than 1 year!  Of course that’s a minimum expected lifetime, and is also dependent on voltage, temperature, and other factors.

TVs and DVD players are designed with a “standby” mode – reduced operation but able to be powered up using a remote control. Clearly, some parts must remain active for this to work.  The bloke who fixed the TV said this is why TVs etc should be turned off at the wall when not in use.

Ok, so the other DVD player. It worked, but would freeze about 53 minutes into a movie.  That’s about the point where the laser has to refocus onto the 2nd layer of the disc. I cleaned the lens; no improvement. I watched it start up with the cover off; the laser assembly was moving up and down appropriately. I did notice on the power supply board, one capacitor looking slightly bulgy, and another one had a brown deposit around it. Another order, replace those 2 caps, and this player is back in business too! It still has a problem with one particular disc, but otherwise appears to be back to normal.

Rubbish

Last week at the tip, I saw quite a range of electronic equipment piled together.  (Our rubbish tip doesn’t charge, but does segregate waste types and restricts what can go into landfill).  It made me wonder.. how many TVs, stereos, DVD players just need a couple of capacitors changed?  How many microwave ovens only need a new magnetron?

On the same trip, I found in the “green waste” (garden) section, a portable electric fan, new in box. Its problem? One leg was missing.

Economics

One of the downsides of production lines, automation, and cheap labour in distant countries, is that many items can are cheaper to construct something and ship it around the world than to repair or maintain. I could buy a basic new DVD player, as good as our older one, for $50. If I were to pay a technician to repair and test a DVD player in this state, it might take half an hour if he had the right parts in stock. I doubt the bill would be less than $50 for labour plus $10 in parts, and there’s the risk of other problems making it a bigger job.

Or, for $120, I could buy a new Blu-ray player that also accepts data cards from cameras, and recognises photos, songs and movies stored elsewhere on my home network.

So, mostly people accept the lazy economics of “just buy a new, better, replacement”.  Even more so with printers, which are sometimes so heavily subsidised that a replacement ink/toner cartridge costs more than the printer itself.

Appliances could have greater longevity. They could be upgradeable. They’re not, because consumers are more focused on the up-front price. And, people are lazy in their affluence.

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