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[sevenlayermuddle]

I've just spent an afternoon getting to the bottom of a networking performance problem that randomly afflicted various systems on my LAN.  The common denominator turned out to to be a two year-old Netgear GS 608 gigabit switch.   There were no outward signs of problems, and all connected machines were negotiating a gigabit connection.  But inspection of LAN stats on connected machines showed a high error rate in all packets forwarded by that device, so that it was lucky to sustain an actual data rate of 10 Mbits, let alone a gigabit.

Upon dismantling, it was apparent that a couple of electrolytic capacitors were bulging and fit to burst - which is a common sign of failure.  I happened to have some suitable low ESR caps in my components cupboard and, after replacing the bulging capacitors, the switch is performing perfectly again.  Satisfying, yes,  but it shouldn't have been necessary.  And the majority of people would have just forked out £40 or more for a new switch.

This is the second time a bit of Netgear kit has failed prematurely on me with bulging capacitors - the first was a DG834GT router.  I'm aware that electrolytic capacitors are notoriously unreliable at the best of times, but the problem can be reduced by purchasing high quality (higher cost) items, or by 'over-specifying' the temperature rating - capacitor MTBF is related to temperature, so by using higher temp ratings, they can be made to last longer.

Earlier in the year a PSU failed in one of my Linux-based set-top boxes, at just over a year old.  It was an unknown chinese brand, in a non-standard enclosure (MINI ATX), so although a dead PSU would normally just be discarded and replaced, component-level repair was the only option.  There again, all that was needed was replacement of no less than eight bulging caps.   The majority of folks on that occasion would have probably have resorted to replacement of the entire PC, losing several hundred pounds.

What a shame the manufacturers won't spend an extra buck and install better quality components.  There's only three caps in total inside the switch I just repaired, so they really would have added very little to the cost.

Anyway, I just thought I'd have a bit of a grump about it all. 

[CurlyWhirly]

This is the second time a bit of Netgear kit has failed prematurely on me with bulging capacitors - the first was a DG834GT router.

Sorry to hear about your problems

My Netgear DG834GT is around 3 years old and still going strong thankfully.

[sevenlayermuddle]

This is the second time a bit of Netgear kit has failed prematurely on me with bulging capacitors - the first was a DG834GT router.

Sorry to hear about your problems

My Netgear DG834GT is around 3 years old and still going strong thankfully.

Thanks for the sympathy, but I assure you these problems are not just mine, they are industry wide. For an example, see

http://en.wikipedia.org/wiki/Capacitor_plague

Actually I'm not sure I really believe in the 'plague' as described in the wiki article, I think it's more just the fact of life that if you run a cheap (aluminium) electrolytic capacitor anywhere near it's rated temperature, it's life expectancy will be very short.  The manufacturers MTBF charts tend to acknowledge that much.  I'm also aware that Netgears are highly regarded and justly so, and a 3-year old example is not unusual.  But when I look inside the box I'm hard pushed to see any single component that would stand much chance of failure inside twenty years, let alone 3 years, except these cheap aluminium electrolytics....

[roseway]

I suppose if you were really keen to preserve a particular router, you might replace all those aluminium electrolytics with tantalum types (but be sure to connect them the right way round!).

[sevenlayermuddle]

(but be sure to connect them the right way round!).

Wise words.  I once accidentally connected the batteries the wrong way around to a circuit decoupled by a tantalum capacitor.  It took only a few seconds before there was a loud 'pop' as the end flew off the capacitor, leaving a tiny candle-like flame burning for a few seconds in the capacitor body.   

But even just good quality aluminium components would be a huge improvement.  It does seem to be the Taiwanese components, from manufacturers I've never heard of, that die early deaths.  I've stocked up on a selection of good quality  Panasonics that I use to replace them when repairs are worthwhile.   

BTW I notice our 4 year old Dell Dimension has two badly failed capacitors on the motherboard.  But as it's still working fine, and it's mainly used by Other Half, I'll leave it alone.   Attacking a motherboard with a soldering iron scares me a bit, and she'd never forgive me if I killed it with my surgery. 

[roseway]

Attacking a motherboard with a soldering iron scares me a bit,

I agree. Motherboards are multilayer things with very fine tracks, and very easy to damage with a soldering iron.