On Sat, 08 Dec 2012 12:31:49 -0700, Jim Thompson
wrote:

What's with wall warts? Do they have a five year warranty clock
built-in?

Yes. The conspiracy theory is that components are selected to survive
no longer than the warranty period.

I just lost the third wall wart in a month.

Check your AC voltage. It may be on the high side.

All of them 5+ years old, or more, so I guess I can't complain.
What's to wear out... capacitors?

Yes. Also sometimes a thermal fuse. Linksys makes two types of wall
warts. Your antique is almost surely just a transformer, diode
bridge, and electrolytic capacitor. To provide minimal voltage
regulation, the transformer is run just below saturation, which causes
some heating. The newer types use a switching power supply. They
draw no power without a load, are more efficient, but are more
sensitive to power line transients. They also tend to spew EMI/RFI.
As usual, they kill electrolytics:
http://802.11junk.com/jeffl/pics/repair/slides/2Wire-power-supply.html
http://802.11junk.com/jeffl/pics/repair/slides/Netgear%20DSA-12R-12.html
http://802.11junk.com/jeffl/pics/repair/slides/Motorola-2210-02-PS.html

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

Ummm... yeah, that's ancient. There are 4 different hardware
versions. From the release notes, the earliest version was Aug 2000
and the latest was last updated in Sept 2009. Yours is somewhere in
between.

I'm presently up and running on a bench supply :-}

Need some spare wall warts?
http://802.11junk.com/jeffl/pics/e-waste/slides/wall-warts.html
That's about a 3 week collection at the local recycling center.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558