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Arfa Daily Arfa Daily is offline
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Default Yahama Stagepas-300



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"Stephen Birchall" wrote in message




No matter how much that I pointed
out that the real life evidence of bathtub curves and infant mortality,
clearly refuted that premise, they were not having any of it. They seemed
unable to understand that a board that has been in service for a while
has
passed the infant mortality stage, and is fully burnt in. And that it is

in
the main phase of its service life, where any problems are likely to be
random single component failures. None of the parts on this board were
specials, so it could have been repaired to full manufacturer's spec,

using
original manufacturer's parts. In fact, the triac that seemed to be

failing
could actually have been upgraded to the next one in the series to

*improve*
overall reliability.

But here's the really silly bit. Another board in the machine, which I
already repair for them, suffers a faulty tactile switch on a regular

basis.
So I asked if they were going to stop having that repaired as well. Oh
no,
they said. We can carry on doing that one, because it's only a
replacement
switch. Slowly banging my head on the bench, I asked them why they felt

that
replacing that single switch was any different from replacing a single
triac, and how they felt that a board that was repaired by having that
switch put in, would be any more reliable than a board that had been
repaired by having a triac put in it. There was no answer, because they
really couldn't see the logic ...

To be fair, the guy that I deal with direct, was with me on this, but his
hands were tied from further up the food chain. What bothers me most is

what
happens to all of the faulty boards. Do they just become scrap destined

for
landfill ? Bit of a waste ...

Arfa



I've come across the concept of failure-rate variability over time etc but
I
think the term of a bathtub plot is new to me.
Joins the hockeystick, J, bell, and dead-cat bounce




Well, I don't know about that. I was taught it at college over 40 years ago,
so it's not some new fangled concept. If you put the term into Google, you
will get many thousands of hits on the subject, including modern
interpretations.

Arfa