On Mon, 22 Sep 2014 12:59:49 -0400, "Jim Wilkins"
wrote:

"pyotr filipivich" wrote in message
.. .
Ed Huntress on Mon, 22 Sep 2014 09:35:46
-0400 typed in rec.crafts.metalworking the following:

Or, as they used to say at GM, "Any damned fool can design a
carburettor for a Rolls-Royce. It takes a genius to design one for a
Chevrolet."

Or the tongue-in-cheek motto applied to Mercedes-Benz: "Never use
two
parts to do a job when you can get away with three." g

OTOH, when you have three parts, you can replace one of them. B-)

Nowadays, we have modules which are plug and play, do multiple
functions, and can't really be repaired. Not cost effectively,
compared to removing and replacing.
--
pyotr filipivich

That started in the 1980's with surface-mount electronics, which are
substantially more difficult to repair by hand than thru-hole, and not
reliable unless the tech who solders on the new parts is more than
usually skilled and experienced. I got the experience on lab
prototypes where a solder failure was only a brief inconvenience
instead of costing a field service call.

Compared to thru-hole SMT is very cheap to manufacture, costing little
more to make than the Bill of Materials, and the ICs themselves are
cheaper to make due to the smaller lead frame with much less metal. I
first encountered the no-repair policy on computer add-in cards for
Winchester drives, when the vendor didn't want us to return defective
ones.

The Army taught us troubleshooting to the transistor level. They had
so much difficulty finding recruits who could learn it that they
changed to training LRU (Line-Replaceable Unit) board-swappers. The
four (of ~80) of us who graduated all had science degrees. The
washouts had a choice of other repair schools so they weren't wasted.
-jsw

You would have appreciated the board-level repairs I had to make, in a
shirt and tie, at the Rocky Flats bomb plant. We had sold a Sodick EDM
to them and we had to fly out to do a repait -- two young Japanese
guys from our staff, one an engineer and the other a technician, and
me (Marketing Manager).

But they make (or made) nuclear-bomb triggers there and the Japanese
couldn't get past the lobby. So they sent me in with some test
equipment and got on the phone with me. We had a box of discrete parts
and the boards with us that we thought were the problem, but that
wasn't it. So I had to solder a couple of components right on the shop
floor.

Fortunately, they were through-hole, two-side boards, not multi-layer.

--
Ed Huntress (KC2NZT)