[Trevor Wilson]

Further to the recent thread on the Nakamichi amplifier, I did a little
digging. I scanned my own service records and, since I computerised them
(ca: 1989) I was able to work out how many power switches I've replaced in
the last 18 years (around 20,000 repairs). I found that I had replaced 26
power switches. This is across domestic audio equipment almost exclusively.

I work a day or two at a mate's service shop each week. His business
concentrates on video equipment, though he does some audio. He employs
several techs and he performs many more repairs than my business does. His
records are patchy, but he estimates that he has replaced far less than 100
switches in the last 30 years. Presently, he is buying 1,000uF 35 V caps by
the box-load. They are used everywhere in permanent power supplies and they
are failing with frightening regularity. He recently repaired a 20 foot
container full of DVD players (yeah, I know). 99% of them had buggered
capacitors.


Moral: Switch it off, when not in use. The power switches will not fail
(statistically speaking) in a sensible time frame. There are far more
important things to be worried about. (Global warming, capacitor failures,
et al)


--
Trevor Wilson
www.rageaudio.com.au




--
Posted via a free Usenet account from http://www.teranews.com

[Eeyore]

Trevor Wilson wrote:

Further to the recent thread on the Nakamichi amplifier, I did a little
digging. I scanned my own service records and, since I computerised them
(ca: 1989) I was able to work out how many power switches I've replaced in
the last 18 years (around 20,000 repairs). I found that I had replaced 26
power switches. This is across domestic audio equipment almost exclusively.

I work a day or two at a mate's service shop each week. His business
concentrates on video equipment, though he does some audio. He employs
several techs and he performs many more repairs than my business does. His
records are patchy, but he estimates that he has replaced far less than 100
switches in the last 30 years. Presently, he is buying 1,000uF 35 V caps by
the box-load. They are used everywhere in permanent power supplies and they
are failing with frightening regularity. He recently repaired a 20 foot
container full of DVD players (yeah, I know). 99% of them had buggered
capacitors.

Moral: Switch it off, when not in use. The power switches will not fail
(statistically speaking) in a sensible time frame. There are far more
important things to be worried about. (Global warming, capacitor failures,
et al)

Sensible advice Trevor.

Your figures don't surprise me. I wonder how many of those caps were the famous
'bad caps' btw ?
http://en.wikipedia.org/wiki/Capacitor_plague

I've come across a few of them myself but not in large numbers. Rumour has it
that they're highly responsible for the bad name CFLs have in the USA for short
life.


Graham

[Phil Allison]

"Eeysore Rumour Monger "

http://en.wikipedia.org/wiki/Capacitor_plague

I've come across a few of them myself but not in large numbers. Rumour has
it
that they're highly responsible for the bad name CFLs have in the USA for
short
life.



** The defective "plague" caps were all low voltage, high value, low ESR
types.

So *nothing* like what is used inside a CFL - where the electro is
typically 4.7 uF at 200 volts for the USA.

A high ESR electro ( several ohms) is desirable in a CFL to limit inrush
current when many are on the same cct.



....... Phil

[Dave Plowman (News)]

In article ,
Trevor Wilson wrote:
Presently, he is buying 1,000uF 35 V caps by the box-load. They are
used everywhere in permanent power supplies and they are failing with
frightening regularity. He recently repaired a 20 foot container full
of DVD players (yeah, I know). 99% of them had buggered capacitors.


Moral: Switch it off, when not in use. The power switches will not fail
(statistically speaking) in a sensible time frame. There are far more
important things to be worried about. (Global warming, capacitor
failures, et al)

What would make it easier to persuade people to switch things off would be
legislation to force makers to use non volatile memory etc so you didn't
have to re-set stuff each time you switched on.

--
*It was recently discovered that research causes cancer in rats*

Dave Plowman London SW
To e-mail, change noise into sound.

[tony sayer]

In article , Eeyore rabbitsfriendsandrel
writes


Trevor Wilson wrote:

Further to the recent thread on the Nakamichi amplifier, I did a little
digging. I scanned my own service records and, since I computerised them
(ca: 1989) I was able to work out how many power switches I've replaced in
the last 18 years (around 20,000 repairs). I found that I had replaced 26
power switches. This is across domestic audio equipment almost exclusively.

I work a day or two at a mate's service shop each week. His business
concentrates on video equipment, though he does some audio. He employs
several techs and he performs many more repairs than my business does. His
records are patchy, but he estimates that he has replaced far less than 100
switches in the last 30 years. Presently, he is buying 1,000uF 35 V caps by
the box-load. They are used everywhere in permanent power supplies and they
are failing with frightening regularity. He recently repaired a 20 foot
container full of DVD players (yeah, I know). 99% of them had buggered
capacitors.

Moral: Switch it off, when not in use. The power switches will not fail
(statistically speaking) in a sensible time frame. There are far more
important things to be worried about. (Global warming, capacitor failures,
et al)

Sensible advice Trevor.

Your figures don't surprise me. I wonder how many of those caps were the famous
'bad caps' btw ?
http://en.wikipedia.org/wiki/Capacitor_plague

I've come across a few of them myself but not in large numbers. Rumour has it
that they're highly responsible for the bad name CFLs have in the USA for short
life.


Graham


Yes had some motherboard failures with those. Tried replacing one set
but replacing the board is simpler provided all the other components are
matched...
--
Tony Sayer