On Mon, 21 May 2012 07:19:34 -0700, the renowned "William Sommerwerck"
wrote:

Those horribly unreliable TVs with "the works in a drawer"
were pretty amusing. Talk about turning a bug into a feature.

Ahh, that was at least 40 years ago, and used vacuum tubes!

The "Quasar" models were transistor sets (circa 1964, I believe). I remember
a trade journal remarking that Motorola had gotten all-transistor color TV
to market two years before it was anticipated.

The "works in a drawer" were intended to simplify service. The technician
simply swapped boards (assuming the problem wasn't something not on the
boards). Motorola's goal was to keep track of what failed, and gradually
improve the boards' reliability.

Of course, a system of individual boards is inherently more-expensive than
"works on A board", not to mention the need to standardize signal levels and
power voltages. It was economically doomed from the start. But it was a good
idea.

The proof of this is that we now repair equipment the same way -- we simply
replace "everything", either by tossing out the single over-populated
circuit board, or the product altogether.

Most industrial products (and automotive, and computer, and appliance)
are still repaired like the Quasar sets- replacement at the module
level, followed by rebuilding (maybe) or discarding (often) the bad
module.

We don't generally replace the whole product except on low end and on
TVs- we swap out a power supply, an LCD screen or keyboard, a dying
lithium battery or a refrigerator thermostat.

With transistorized (and especially IC) TVs, they became so reliable
that adding money to simplify repairs became a liability. Most of us
have dumped perfectly working 20+ year old Sony etc. TVs who's only
offense was to be become out of fashion and unattractive compared to
their newer bretherin.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com