Joe wrote:

On Wed, 20 Jan 2010 16:00:13 -0500, "Michael A. Terrell"
wrote:


Joe wrote:

On Wed, 20 Jan 2010 10:25:38 -0600, Frnak McKenney
wrote:

On Tue, 19 Jan 2010 13:20:00 -0500, Joe wrote:


Yeah, that sucks. SMT has had a generally positive impact on
technology, but has also limited the ability of people to do
component-level repairs. There's a lot of waste in throwing away a
fully populated board that contains only one bad component. In the
industrial environment I work in, we often throw entire VFD motor
drives (big 'uns - 30 HP on up) away, 'cause there's no way to
troubleshoot it, the manufacturer won't support the old stuff and
won't release the schematics and other info.

Joe

On the other hand, the parts on such boards can be reused. It _is_
possible to salvage (some) SMT parts for your own projects if you're
willing to trade time and effort for money. If you're interested,
you can find comments pro and con from a number of 'web sites, and
you'd be surprised at what can be accomplished with a hair-dryer and
a bucket (I'll also recommend heavy gloves).

I've extracted parts with a heat gun myself, although so far only to
collect stuff to practice soldering with. I remember what it was
like extracting 1/2W resistors and ceramic discs from open-chassis
radios and TV sets, and later from PC boards; I suspect that the
recovered-to-damaged ratio is about the same. (A one-lead 1/2W
resistor isn't all that useful. grin!)


Frank

I've salvaged lots of stuff from the drives, but not SMT chips; just
too much trouble to adapt them for my purposes. I used to glom onto
the heat sinks, but now I've got so many that I've had to throw away
(Gasp!) some of my stash just to make room for other things. Muffin
fans get saved or passed on to others, toroids & ferrite cores always
come in handy. Even the passive components are usually SMT now; I've
got a good supply of old carbon comp and carbon film for my future
needs. Tons of mylar caps, too. I always keep AC caps, though.

Nowadays most of the electronics I putz with is audio-related; even
got a few tube amps from the early 60s I plan to rework. (Maybe a
direct-drive ES headphone amp?)

Workwise, I do metrology now.


My last job was building high end telemetry equipment at Microdyne,
but I spent some time in our Metrology lab as well. The old man that ran
the lab wasn't familiar with some of the newest types of ICs, and I
worked with them all day long so I would help him out when he ran into
trouble.

Have you ever seen the Microdyne TS-2000? It was a custom test set
for calibrating Telemetry receivers.

Although telemetry would be a good fit for a few of our applications,
we don't use it at all here. The bulk of my work is with temperature;
most of the remainder is pressure, vacuum (I like vacuum), flow,
level, etc. Everything is carried over some industrial variation of
Ethernet.


Our RCB-2000 and DR-2000 recievers had a Ethernet port. The older
products used RS-232, RS-485 and IEEE-488



--
Greed is the root of all eBay.