Power surges and modern electronics.

[John Keiser]

I am in Hawaii where power surges are unfortunately common. Having lost
several PC power supplies, I now use line conditioning battery backup units
to protect my PCs.
Several months ago I salvaged a Westington flat screen [LTV-32w6 HD] that
had been abandoned because the tuner failed. As the tuner is part of the
motherboard I didn't fix it was easier to use an external VCR as the tuner.
TV functions fine. I assume the tuner died in a power surge.
Yesterday, the power failed and I awoke to find that the TV had turned
itself on but no sound. Toggling mute and adding external speakers did not
work. I assumed the worst but guessed that maybe this was a microprocessor
locked into mute. I unplugged the set and tried again after 15 minutes.
Sound was restored. Whew!
I wonder how many consumers would be so lucky? Is this type of sensitivity
common? [I have a nice old 32inch CRT that has been immmune from these
problems and provides a great picture.] I'll probably add a line
conditioner, but, really, are consumers expected to be that cautious?

 

[William Sommerwerck]

Yesterday, the power failed and I awoke to find that the TV
had turned itself on but no sound. Toggling mute and adding
external speakers did not work. I assumed the worst but
guessed that maybe this was a microprocessor locked into
mute. I unplugged the set and tried again after 15 minutes.
Sound was restored. Whew!

I've experienced this sort of failure with several items -- including an LV
player, a TV set, a PDA, and a DVD player -- over the past 25 years. I call
it "CMOS lockup", though whether that's the actual cause of the problem, I
don't know.

Basically, the product "misbehaves" in some way -- including apparent
"death". Removing the batteries or unplugging it, and then letting it sit
for a while, causes it to be "recalled to life" (Dickens). Sometimes you
need to yank the power cord while the device is running.

I don't know the exact cause, but I suspect it happens often enough that
people discard products that are otherwise perfectly good.

 

On Fri, 10 Dec 2010 07:11:18 -1000, "John Keiser"
<john.keiser2@hawaiiantel.net> wrote:

I am in Hawaii where power surges are unfortunately common. Having lost
several PC power supplies, I now use line conditioning battery backup units
to protect my PCs.
Several months ago I salvaged a Westington flat screen [LTV-32w6 HD] that
had been abandoned because the tuner failed. As the tuner is part of the
motherboard I didn't fix it was easier to use an external VCR as the tuner.
TV functions fine. I assume the tuner died in a power surge.
Yesterday, the power failed and I awoke to find that the TV had turned
itself on but no sound. Toggling mute and adding external speakers did not
work. I assumed the worst but guessed that maybe this was a microprocessor
locked into mute. I unplugged the set and tried again after 15 minutes.
Sound was restored. Whew!
I wonder how many consumers would be so lucky? Is this type of sensitivity
common? [I have a nice old 32inch CRT that has been immmune from these
problems and provides a great picture.] I'll probably add a line
conditioner, but, really, are consumers expected to be that cautious?

There are big differences between the 32" CRT and the 32 inch flat

panel. First, the CRT is the product of more than 50 years of
refinement. Comparitively speaking the flat screen is in it's
infancy.

Second, the CRT set is almost certainly primarily analog. The flat
screen has several processors, and is much more susceptible to
interference.

Third, most flat panel sets are put together out of crappy components,
especially the capacitors. While the power supply might have been
adequate when new, the caps have deteriorated and are allowing noise
from the SMPS onto the power supply rails.

PlainBill

 

[D Yuniskis]

Hi John,

John Keiser wrote:

that
had been abandoned because the tuner failed. As the tuner is part of the
motherboard I didn't fix it was easier to use an external VCR as the tuner.
TV functions fine. I assume the tuner died in a power surge.
Yesterday, the power failed and I awoke to find that the TV had turned
itself on but no sound. Toggling mute and adding external speakers did not
work. I assumed the worst but guessed that maybe this was a microprocessor
locked into mute. I unplugged the set and tried again after 15 minutes.
Sound was restored. Whew!
I wonder how many consumers would be so lucky? Is this type of sensitivity
common? [I have a nice old 32inch CRT that has been immmune from these
problems and provides a great picture.] I'll probably add a line
conditioner, but, really, are consumers expected to be that cautious?

Most modern devices use mmicroprocessors or microcontrollers. Often
*several* (VCRs typically had three or four; my cassette deck has
one just to count capstan revolutions!).

If power fails -- wholly or partially -- it is possible for any
of those processors to reset. Or, *partially* reset. Or, "get
confused" (and head off to never-never land doing something
unintended -- like "executing" *data*).

If the processor doesn't have brownout detection (or it isn;t
implemented properly), a processor can get stuck in one of these
confused states. If the processor doesn't have a hardware
watchdog (or, it isn;t implemented properly), once confused it
can fail to get OUT of that state.

Regardless, sloppy code in one or more of these can result
in them running, but failing to move to their *correct*
operational state. This is a common sort of bug -- the
code makes assumptions (implicitly or explicitly) that,
suddenly, are not valid (because something unforseen has
happened -- e.g., a power glitch between instructions
102,678,993 and 102,678,994). Because the programmer made
those assumptions, he didn't code to protect *against*
them being incorrect.

So, for example, if there are two processors in the set,
they *always* are powered up at the same exact instant
(there is ONLY one power button, right?). And, the code
that they execute never changes. So, 23.0257 milliseconds
after RESET, processor #1 has done <blah> and can now
send the "OK, I am ready to fire up the display" message
to processor #2. Meanwhile, 24.6802 milliseconds after
RESET, processor #2 goes looking for the "OK I am ready"
message, *sees* it (since it was delivered about a millisecond
earlier) and correctly fires up the display.

Now, if something happens that causes processor #1 to come
out of RESET a bit later -- perhaps, 3 milliseconds (e.g.,
maybe power at *it's* reset circuit glitched a bit more than
at #2's; or, it's brownout detector fired *twice* instead of
once) -- then it (#1) might not issue the "OK" message until
26.0257 milliseconds (since it's RESET was 3 milliseconds
later than #2's). Meanwhile, at 24.6802 milliseconds, processor
#2 went looking for the message AND IT WASN'T THERE!!

Had the programmer NOT *assumed* the message *would* be there,
he would have told #2 to wait for it -- for some amount of time.
Instead, he might just crash; or, *incorrectly* (buggy) "wait";
or, fire up the display prematurely causing some other fault
(that shuts him down -- or, something *else* gets shut down), etc.

The heat of almost ALL software bugs is one or more bad assumptions.
When the world behaves in ways programmers don't expect, you
get "anomalous behaviors" -- things that seeem unexplained and
that change without any action on your part to "fix" them.

<shrug> Makes you wonder how *anything* works properly! :-/

(of course, there can also be hardware issues that are causing
this -- like a cap not completely discharging so the circuit
it connects to never sees the "reset")

 

[Bob Villa]

Third, most flat panel sets are put together out of crappy components,
especially the capacitors.

Dell is hoping there are no more of those crappy-caps around!

 

[John Keiser]

Thanks for the details.
Doesn't instill consumer confidence in buying new expensive electronics!



"D Yuniskis" <not.going.to.be@seen.com> wrote in message
news:idu1pq$gb7$1@speranza.aioe.org...

Hi John,

John Keiser wrote:
Several months ago I salvaged a Westington flat screen [LTV-32w6 HD] that
had been abandoned because the tuner failed. As the tuner is part of the
motherboard I didn't fix it was easier to use an external VCR as the
tuner. TV functions fine. I assume the tuner died in a power surge.
Yesterday, the power failed and I awoke to find that the TV had turned
itself on but no sound. Toggling mute and adding external speakers did
not work. I assumed the worst but guessed that maybe this was a
microprocessor locked into mute. I unplugged the set and tried again
after 15 minutes. Sound was restored. Whew!
I wonder how many consumers would be so lucky? Is this type of
sensitivity common? [I have a nice old 32inch CRT that has been immmune
from these problems and provides a great picture.] I'll probably add a
line conditioner, but, really, are consumers expected to be that
cautious?

Most modern devices use mmicroprocessors or microcontrollers. Often
*several* (VCRs typically had three or four; my cassette deck has
one just to count capstan revolutions!).

If power fails -- wholly or partially -- it is possible for any
of those processors to reset. Or, *partially* reset. Or, "get
confused" (and head off to never-never land doing something
unintended -- like "executing" *data*).

If the processor doesn't have brownout detection (or it isn;t
implemented properly), a processor can get stuck in one of these
confused states. If the processor doesn't have a hardware
watchdog (or, it isn;t implemented properly), once confused it
can fail to get OUT of that state.

Regardless, sloppy code in one or more of these can result
in them running, but failing to move to their *correct*
operational state. This is a common sort of bug -- the
code makes assumptions (implicitly or explicitly) that,
suddenly, are not valid (because something unforseen has
happened -- e.g., a power glitch between instructions
102,678,993 and 102,678,994). Because the programmer made
those assumptions, he didn't code to protect *against*
them being incorrect.

So, for example, if there are two processors in the set,
they *always* are powered up at the same exact instant
(there is ONLY one power button, right?). And, the code
that they execute never changes. So, 23.0257 milliseconds
after RESET, processor #1 has done <blah> and can now
send the "OK, I am ready to fire up the display" message
to processor #2. Meanwhile, 24.6802 milliseconds after
RESET, processor #2 goes looking for the "OK I am ready"
message, *sees* it (since it was delivered about a millisecond
earlier) and correctly fires up the display.

Now, if something happens that causes processor #1 to come
out of RESET a bit later -- perhaps, 3 milliseconds (e.g.,
maybe power at *it's* reset circuit glitched a bit more than
at #2's; or, it's brownout detector fired *twice* instead of
once) -- then it (#1) might not issue the "OK" message until
26.0257 milliseconds (since it's RESET was 3 milliseconds
later than #2's). Meanwhile, at 24.6802 milliseconds, processor
#2 went looking for the message AND IT WASN'T THERE!!

Had the programmer NOT *assumed* the message *would* be there,
he would have told #2 to wait for it -- for some amount of time.
Instead, he might just crash; or, *incorrectly* (buggy) "wait";
or, fire up the display prematurely causing some other fault
(that shuts him down -- or, something *else* gets shut down), etc.

The heat of almost ALL software bugs is one or more bad assumptions.
When the world behaves in ways programmers don't expect, you
get "anomalous behaviors" -- things that seeem unexplained and
that change without any action on your part to "fix" them.

shrug> Makes you wonder how *anything* works properly! :-/

(of course, there can also be hardware issues that are causing
this -- like a cap not completely discharging so the circuit
it connects to never sees the "reset")

 

[Charles]

"John Keiser" wrote in message
news:FYWdnYqJUrg7Cp_QnZ2dnUVZ_i2dnZ2d@powerusenet.com...

Thanks for the details.
Doesn't instill consumer confidence in buying new expensive electronics!

D Yuniskis did a nice job but only touched on a few things that can go
wrong. In any case, my thanks to him for taking the time to explain the
issues.

Consumers are becoming more clueless as software takes over their lives.
This is a problem that is becoming more serious. If the doctors and nurses
and technicians in a modern operating room get confused or misled by
software glitches, it could be really, really serious. Has already
happened.

 

[D Yuniskis]

Hi John,

John Keiser wrote:

Thanks for the details.
Doesn't instill consumer confidence in buying new expensive electronics!

I'm not claiming that this is what you *actually* experienced.
But, it is the sort of thing that is commonplace -- increasingly
so, nowadays.

E.g., I have a pair of Nakamichi Dragons (high end cassette decks,
now very "dated"). They are "autoreverse" decks -- when the
tape reaches the end of side A, side B is played (i.e., AS IF
the tape had been "flipped" -- though this is done without
any mechanical motion).

The tape counter, on reaching the end of side A, should start
counting *backwards* as it begins playing side B (i.e., the
counter should end up wherever it originally started once
side B is complete -- assuming you started at the beginning of
side A).

This is, in fact, how it works. There are two "play" buttons
on the deck -- "play forward" (side A) and "play backwards"
(side B). While play forward is active, you will see the
counter increasing. If you press "play backwards", the
counter will *decrease*.

*BUT*... if you stop the tape just as it reaches the end of side
A, open the tape door, remove the tape, flip it over (so, now
side B is "in front"), close the door and press "play forward",
the tape will COUNT BACKWARDS (i.e., as if the tape was still
installed in the deck playing "side B" BACKWARDS). So, the
tape MOVES "forwards" (the machine has no way of knowing that
this is "side 2" of the tape... it may be a completely DIFFERENT
tape!) while the counter counts BACKWARDS!

If you had stopped the tape a second BEFORE it reached the end
of side A, ejected it, flipped it, reinstalled it and pressed
"play forward", the counter would NOT count backwards.

I.e., this is a bug. (technically, a "race") Would you
expect that sort of thing in a $2K device? On something
so *trivial*?? :<

Makes you wonder next time you get on an aircraft ("fly by wire"),
have a surgical procedure ("Doctor, the patient's blood pressure
is 9843 over 2"), etc. :-/

Maybe the Luddites were onto something, afterall! :>

 

[Charles]

Makes you wonder next time you get on an aircraft ("fly by wire"),
have a surgical procedure ("Doctor, the patient's blood pressure
is 9843 over 2"), etc. :-/

Maybe the Luddites were onto something, afterall! :>

Yes, exactly. Coders are very bright (theoretically speaking) folks, but
they cannot see the future. Unanticipated, although normal, events and
other random glitches/failures can conspire to send controllers/chips into
endless loops or into a routine that is entirely inappropriate. We have
engineered ourselves into an untenable position. Anyway, for now, just shut
everything down and turn the devices back on using a recommended sequence
(good luck with that).

 

[D Yuniskis]

Hi Charles,

Charles wrote:

Consumers are becoming more clueless as software takes over their lives.

The problem is that consumers don't *want* to know how things
work or *should* work. And, they don't "vote with their wallet".
They get a crappy product and they either live with it (possibly
not even knowing how crappy it is!) or toss it out and buy another
(probably EQUALLY as crappy)

This is a problem that is becoming more serious. If the doctors and
nurses and technicians in a modern operating room get confused or misled
by software glitches, it could be really, really serious. Has already
happened.

Google "Therac".

Unfortunately, there are no real safeguards in place to *prevent*
this sort of thing happening. There are "practices" that *should*
minimize the chance of it happening. But, there were "practices"
in place that should have prevented "Three Mile Island", etc.

Unfortunately, the folks designing these things have less and less
time, less and less *motivation* and less and less *capability*
for making "robust" products.

My DTV tuner shows *two* "9-1" channels.

Years ago, we would design devices that were (comparatively speaking)
*smart*. They could diagnose their own faults. They could assist
the technician in troubleshooting (set up scope loops, etc.).
Now, everything is reduced to the equivalent of an idiot light
"Service Required" -- and, often, that light isn't even present!
The device just "acts funny". And, since users often don't know
how it truly *should* work, they can't AUTHORITATIVELY complain/deduce
that it *is* malfunctioning.

(how many VCR's blink 12:00? Do you have to be a rocket scientist
to set the clock on a VCR???)

I have a Zune media player (movies, music, etc.). I am convinced the
hard drive inside it is dying. Instead of a diagnostic message to
that effect appearing on the LARGE, COLOR, FULL GRAPHIC DISPLAY, the
device sits there trying to read from the disk endlessly (locking
up in the process). "Um, if it can't get the data on the first,
second or even three hundredth attempt, what makes you think it will
get it on the 9 millionth attempt two days from now???"

Instead of helping the consumer determine that he has a p[roblem
(or, better yet, RECOVERING from that problem), it sits there
frustrating the user and leaving him with no alternative other
than to:
- call tech support (in some third-world country, no doubt)
- google for similar symptoms
- discard it in frustration

 

[Charles]

"D Yuniskis" wrote in message news:idu8ba$1k2$1@speranza.aioe.org...

Hi Charles,

Charles wrote:

Consumers are becoming more clueless as software takes over their lives.

The problem is that consumers don't *want* to know how things
work or *should* work.

Well, if you meant that they are not willing to expend any effort to learn
about their possessions, then you are correct.

And, they don't "vote with their wallet".
They get a crappy product and they either live with it (possibly
not even knowing how crappy it is!) or toss it out and buy another
(probably EQUALLY as crappy)

I shudder at the amount of functional items that are returned, or re-sold,
or sent to landfills and recycling centers. The waste is a pox on our
future. The planet Earth is a finite resource!

This is a problem that is becoming more serious. If the doctors and
nurses and technicians in a modern operating room get confused or misled
by software glitches, it could be really, really serious. Has already
happened.

Google "Therac".

Unfortunately, the folks designing these things have less and less
time, less and less *motivation* and less and less *capability*
for making "robust" products.

Nor are they concerned about tomorrow, unless it's about their stock
options.

My DTV tuner shows *two* "9-1" channels.

The -1 channels here are not always available (high-def) and there is no
discernible rule of thumb to guide one as to why.

- call tech support (in some third-world country, no doubt)
- google for similar symptoms
- discard it in frustration

Toss it out. That's what too many folks are doing. Horrible!

 

[D Yuniskis]

Hi Charles,

Charles wrote:

Makes you wonder next time you get on an aircraft ("fly by wire"),
have a surgical procedure ("Doctor, the patient's blood pressure
is 9843 over 2"), etc. :-/

Maybe the Luddites were onto something, afterall! :

Yes, exactly. Coders are very bright (theoretically speaking) folks,

<frown> You are more "generous" than I! :>

but they cannot see the future. Unanticipated, although normal, events
and other random glitches/failures can conspire to send
controllers/chips into endless loops or into a routine that is entirely

But, you needn't "see the future" to code against these things!
All you have to do is step back (figuratively) and look at
your design and ask yourself: "What have I taken for granted,
here?" Then, go back and "UN"-take it for granted.

Of course, there are some things that you *have* to "assume".
But, far less than you actually usually *do* assume (at least
if you want a robust design!).

E.g., if you loan someone money, do you *assume* you will be
paid back AND HAVE NO CONTINGENCY PLANS FOR THE POSSIBILITY
OF *not* BEING PAID BACK? (if so, I'd like to speak to you
about a loan... :> )

inappropriate. We have engineered ourselves into an untenable
position. Anyway, for now, just shut everything down and turn the
devices back on using a recommended sequence (good luck with that).

 

[Jeff Liebermann]

On Fri, 10 Dec 2010 12:11:00 -0800 (PST), Bob Villa
<pheeh.zero@gmail.com> wrote:

Third, most flat panel sets are put together out of crappy components,
especially the capacitors.

Dell is hoping there are no more of those crappy-caps around!

Dell was not using "crappy" capacitors. What they were doing is the
same thing that almost every other manufactory is currently also
doing. They are rating their electrolytics as close to the bitter
edge of failure as possible. That saves a few pennies in cost by
using a lower voltage electrolytic but shortens the capacitor life. My
guess(tm) is that Dell's OEM supplier in China selected the capacitors
based upon faulty calculations, where it was designed to blow up in
about 5 years, instead of the 1-2 years specified in the class action
suit.

"Determining end-of-life, ESR, and lifetime calculations for
electrolytic capacitors at higher temperatures"
<http://www.dfrsolutions.com/uploads/white-papers/Uprating_of_Electrolytic_Capacitors.pdf>
At the bottom of the paper, note the various ways in which the ESR can
climb as a result varying conditions. At 105C (rated max temp), a
typical capacitor will have its ESR increase 5 times (and therefore 5
times the dissipation) after 3500 hrs of normal operation. For
24hr/day operation, that's only about 5 months of continuous
operation.

This has nothing to do with the original question, but I thought it
might be interesting.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

 

[D Yuniskis]

Hi Charles,

Charles wrote:

Consumers are becoming more clueless as software takes over their lives.

The problem is that consumers don't *want* to know how things
work or *should* work.

Well, if you meant that they are not willing to expend any effort to
learn about their possessions, then you are correct.

Yes. And, most of those things aren't designed to *encourage*
comprehension. How many things have *no* power switch -- leaving
you pushing buttons wondering which will "turn it on"?

And, they don't "vote with their wallet".
They get a crappy product and they either live with it (possibly
not even knowing how crappy it is!) or toss it out and buy another
(probably EQUALLY as crappy)

I shudder at the amount of functional items that are returned, or
re-sold, or sent to landfills and recycling centers. The waste is a pox
on our future. The planet Earth is a finite resource!

<shrug> I do volunteer work at a place that recycles "stuff".
I think we processed 1000 tons last year. Depressing to see
the things people just "abandon" (effectively) that still work.

Somewhere (and I'll be damned if I can recall where!), I saw an
article discussing natural resources. The point of the article was
"whatever is here is *all* there will ever *be* of these things"
(unless the alchemists succeed!). I.e., all of the Copper on
(in) the planet was formed when the planet was formed; we don't
"grow" copper to replace what we use.

For each of these resources (copper sticks in my mind), the article
described where it "was", currently.

IIRC, for copper, 1/4 of it is "in use"; 1/4 of it is "in landfills";
1/4 of it is "waiting to be mined/harvested"; 1/4 is unharvestable.
I.e., one way of looking at this is: we have used 2/3 of the copper
available to us, already (in the past ~100? years) and that half
of that is "in the trash".

There are other interpretations that are more pessimistic or less;
but, the bottom line is "there is only so much"...

<shrug>

This is a problem that is becoming more serious. If the doctors and
nurses and technicians in a modern operating room get confused or
misled by software glitches, it could be really, really serious. Has
already happened.

Google "Therac".

[really... do it!]

Unfortunately, the folks designing these things have less and less
time, less and less *motivation* and less and less *capability*
for making "robust" products.

Nor are they concerned about tomorrow, unless it's about their stock
options.

Correct. OTOH, there is no motivation *to* be concerned about
those things. "It's someone else's problem"...

My DTV tuner shows *two* "9-1" channels.

The -1 channels here are not always available (high-def) and there is no
discernible rule of thumb to guide one as to why.

But why *two* of them (in addition to 9-2, etc.)...

- call tech support (in some third-world country, no doubt)
- google for similar symptoms
- discard it in frustration

Toss it out. That's what too many folks are doing. Horrible!

<shrug> Again playing devil's advocate: what is the alternative?
Anything I fix "for myself" is "affordable" (for me). But, if I
have to fix something for someone *else*, it quickly becomes
prohibitively expensive to do so (I don't work for free). The
"system" assigns no cost to discarding items. So:

discarding + replacing <= keeping + repairing

 

[William Sommerwerck]

How many VCR's blink 12:00? Do you have to be a rocket scientist
to set the clock on a VCR???

In some cases, yes. Some had setting procedures that went beyond
unbelievable.

 

[Jeff Liebermann]

On Fri, 10 Dec 2010 07:11:18 -1000, "John Keiser"
<john.keiser2@hawaiiantel.net> wrote:

I am in Hawaii where power surges are unfortunately common.

I live in the forest in the Santa Cruz Mountains. When the wind blows
or it rains, the branches and the power lines tend to meet, resulting
in power glitches.

If it makes you feel any better (probably not, but worth a try), after
every storm, I get a few calls from customers with hung network and
entertainment equipement. DSL modems, cable modems, routers,
switches, IP phones, wireless, computahs, security systems, DVR's,
printers, TIVO, etc. Just about anything with a microprocessor inside
can be made to hang. D Yuniskis covered races and hazzards so I won't
go there. Add to that the joy of memory (RAM) glitches. When the
power fluctuates, one of the most sensitive components is the common
serial or dynamic RAM commonly found in almost everything. A
momentary magnetic pulse from a nearby power xformer is usually
sufficient to produce a large enough field to flip a few bits. You
may not even notice that a few bits have been flipped until perhaps
days after the power glitch, when the operating system decides to use
those memory cells, and finds them in a bizarre state. This is why
many servers have ECC (error correcting) RAM.

The problem of unpredictable processor operation is well known as are
some of the band-aids. For low end hardware, usually nothing is done.
Just power cycle the box if it hangs. Some clever programmers add in
a watchdog timer, which monitors the state of some manner of commonly
updated register (i.e. the RTC) and reboots the device if it goes
comatose. While clever, it's not very reliable as the dead-mans timer
is part of the same processor that it's trying to protect. An
external watchdog timer works much better. It usually receives a 1
PPS (one pulse per sec) signal from the processor. If that
disappears, it's reboot time.

It isn't just power line glitches that cause hangs. Cosmic rays,
alpha particles from radioactive components, external fields, and bit
rot all contribute to the general lack of uptime.

Anyway, try not to worry too much. Features and functions are added
faster than bugs get fixed, so reliability and uptime rapidly some
minimum acceptable value. This value is usually set by when the
support phone starts ringing. When the customer complaints arrive,
it's probably time to fix the problem. Otherwise, few people complain
about ocassional hangs, crashes, and reboots.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

 

[D Yuniskis]

Hi William,

William Sommerwerck wrote:

How many VCR's blink 12:00? Do you have to be a rocket scientist
to set the clock on a VCR???

In some cases, yes. Some had setting procedures that went beyond
unbelievable.

I don't think that applies to anything manufactured in the last
20 years... :<

Rather, I think it is a tradeoff of value for effort. E.g., my
TV has a clock in it. I've never set it. Reasoning: it's not
normally visible (I would have "to turn it on" to see it and
then it would interfere with the picture displayed; setting it
requires navigating through four or five screens of settings
(i.e., a bit of effort); and, it doesn't offer me any value
(that I can't get just by looking over my shoulder to the clock
that displays time REGARDLESS of whether or not the TV is on!).

I suspect most VCRs were used for watching movies instead of
timeshifting. In that case, there is no value to having the
correct time set (it may not even be visible while the movie
is playing!). And, since most VCRs wouldn't *retain* their
time settings in the face of power interruptions (power
outages, unplugging the set, etc.), it doesn't take long for
a clock to fall into the "ignored" category.

Finally, too many timepieces in a home ends up relegating most
of them to "un-maintained" -- how many of us have *a* clock
that we consider The Authority in our homes (i.e., we expect
some amount of error in all the others -- intentional or
otherwise)

 

[William Sommerwerck]

How many VCR's blink 12:00? Do you have to be a
rocket scientist to set the clock on a VCR???

In some cases, yes. Some had setting procedures that
went beyond unbelievable.

I don't think that applies to anything manufactured
in the last 20 years... :

Perhaps. But I've seen them.

Some years ago VCRs were redesigned to, at turn-on, scan the broadcast band
for a station with an embedded time code, and set the clock. These were
usually NPR stations.

Finally, too many timepieces in a home ends up relegating most
of them to "un-maintained" -- how many of us have *a* clock
that we consider The Authority in our homes (i.e., we expect
some amount of error in all the others -- intentional or
otherwise).

I do. I have two atomic clocks.

 

[D Yuniskis]

Hi William,

William Sommerwerck wrote:

How many VCR's blink 12:00? Do you have to be a
rocket scientist to set the clock on a VCR???

In some cases, yes. Some had setting procedures that
went beyond unbelievable.

I don't think that applies to anything manufactured
in the last 20 years... :

Perhaps. But I've seen them.

Some years ago VCRs were redesigned to, at turn-on, scan the broadcast band
for a station with an embedded time code, and set the clock. These were
usually NPR stations.

Dunno. I haven't used a VCR in more than 20 years :-/
(The one that still is in use here is only used for playing
prerecorded tapes)

Finally, too many timepieces in a home ends up relegating most
of them to "un-maintained" -- how many of us have *a* clock
that we consider The Authority in our homes (i.e., we expect
some amount of error in all the others -- intentional or
otherwise).

I do. I have two atomic clocks.

I had one here -- but it always kept losing signal. So, you
get a false sense of security *thinking* it is telling the correct
time -- only to discover it wasn't. I guess they are sensitive to
where they are located/oriented. Given how "unattractive" this one
was (think: functional not decorative), the choices for where it
could acceptably be sited were limited. So, it got relocated -- to
the trash. :<

(It *was* fun, though, to watch it go into "set" mode... minute hand
sweeping across the face of the clock as if it was a *second* hand...)

 

[William Sommerwerck]

I had one here -- but it always kept losing signal. So, you
get a false sense of security *thinking* it is telling the correct
time -- only to discover it wasn't. I guess they are sensitive to
where they are located/oriented. Given how "unattractive" this
one was (think: functional not decorative), the choices for where
it could acceptably be sited were limited. So, it got relocated --
to the trash. :

Such clocks are best kept away from computers and other sources of EMI/RFI.
Once you find a clean spot, you should be okay.

Those with LCDs usually have an indicator that shows whether the clock has
been recently resynched.