On 03/01/15 13:03, polygonum wrote:
On 02/01/2015 19:22, William Sommerwerck wrote:
His basic premise makes sense -- more components = lower reliability --
but the fact is that one can easily find electronic devices 50 and 60
years old that have never been serviced that continue to work. Members
of this group probably own them.

A failure rate of 1 in 10,000 (per year?) strikes me as unduly
pessimistic, even for devices used in vacuum tube equipment. Solid-state
-- which almost always operates at lower voltages and temperature --
should be even more reliable.

I own devices that contain far more components than an LED bulb -- yet
they do not drop like flies. Flat-panel TVs are a good example. CU says
the reported breakdown rate is extremely low (3% for a few brands is on
the high end), and advises against purchasing service contracts.

Though the point he raises is valid, and not only deserves, but
requires, study, you can't assume these products fail prematurely simply
because they contain "too many parts". Why they failed is more
important. I wouldn't be surprised if it was due to SMD soldering
failure.


The Haswell-E die is composed of 2.6 billion transistors. You have to
achieve phenomenal component reliability for any of them to work as they
leave the factory, let alone years later! Adding up everything in a
typical modern PC including the display leads to even huger numbers of
components. Yet we see many of them struggle on for many years until
they are replaced, all too often, due to inadequate computing power (or
not being able to justify the complete re-install of an updated OS on an
old box) rather than component failure.

The deeper analysis asks the question 'what fails, and why?'

In general a chip once made, wont degrade catastrophically. Its
thermally stable, and any manufacturing faults show up on test or early on.

Yes, RAM and other chops do age, but there is a wide tolerance before
they go so far out of spec they are useless.

By far the greatest killer is heat: heat accelerates ageing., death
occurs in microseconds at 180C, decades at 30C



--
Everything you read in newspapers is absolutely true, except for the
rare story of which you happen to have first-hand knowledge. €“ Erwin Knoll