Toshiba TV29C90 problem; Image fades to black...

[David Maynard]

JW wrote:

On Fri, 15 Oct 2004 01:52:52 -0700 "Watson A.Name - \"Watt Sun, the Dark
Remover\"" <NOSPAM@dslextreme.com> wrote in Message id:
10mv4q1pn2vcv29@corp.supernews.com>:


"CBFalconer" <cbfalconer@yahoo.com> wrote in message
news:416F7B74.E4EAAB68@yahoo.com...

larrymoencurly wrote:

"Chip" <anneonymouse@virgin.net> wrote in message:


"Qtec" - for example - are a very popular low-end brand. You
might refer to them as a no-name, but arguably they are one step
up from that. They produce a very popular 550w PSU.

The first thing to note is that by 550w, they mean *Peak*. Which
basically means nothing at all.

I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power. Is it a
sign of greater honesty, or of lower standards?

Are you sure that Q-tec is a step above no-names? This picture of

the

insides of their 550W model:

www.bit-tech.net/images/review/123/7.jpg

Makes i seem more like a decent 250W.


5 Va.c. _________\|____ 1 k ohm ___________________ 5 V out
/| | |
diode | |
1000 uF 5V zener
|________|
|
gnd

should provide 5v regulated with a 600 or more peak power output
rating. Depends only on the quality of the capacitor. Maybe I
should go into business.

600 or more _what_?


I'm assuming he meant watts,

"Peak" watts.

but...


Where do you get 5VAC?


More importantly, if he did mean watts, I'd like to see how it'll get
through that 1k resistor

Easy. It charges the capacitor back up, over time.

 

[Tom MacIntyre]

"Chip" <anneonymouse@virgin.net> wrote in message news:<2t7c2mF1shd7gU1@uni-berlin.de>...

"Qtec" - for example - are a very popular low-end
brand. You might refer to them as a no-name, but arguably they are one step
up from that. They produce a very popular 550w PSU.

The first thing to note is that by 550w, they mean *Peak*. Which basically
means nothing at all.

It means that they must have been manufacturers of computer speakers
before they started with power supplies?

Tom

 

[kony]

On Fri, 15 Oct 2004 20:27:36 GMT, Tom MacIntyre
<tom__macintyre@hotmail.com> wrote:

"Chip" <anneonymouse@virgin.net> wrote in message news:<2t7c2mF1shd7gU1@uni-berlin.de>...

"Qtec" - for example - are a very popular low-end
brand. You might refer to them as a no-name, but arguably they are one step
up from that. They produce a very popular 550w PSU.

The first thing to note is that by 550w, they mean *Peak*. Which basically
means nothing at all.

It means that they must have been manufacturers of computer speakers
before they started with power supplies?

Tom

LOL, that's exactly what i was thinking.

 

[Watson A.Name - \"Watt Su]

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10mvdnhjiksdf1@corp.supernews.com...

JW wrote:

On Fri, 15 Oct 2004 01:52:52 -0700 "Watson A.Name - \"Watt Sun, the
Dark
Remover\"" <NOSPAM@dslextreme.com> wrote in Message id:
10mv4q1pn2vcv29@corp.supernews.com>:


"CBFalconer" <cbfalconer@yahoo.com> wrote in message
news:416F7B74.E4EAAB68@yahoo.com...

larrymoencurly wrote:

"Chip" <anneonymouse@virgin.net> wrote in message:


"Qtec" - for example - are a very popular low-end brand. You
might refer to them as a no-name, but arguably they are one step
up from that. They produce a very popular 550w PSU.

The first thing to note is that by 550w, they mean *Peak*. Which
basically means nothing at all.

I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power. Is it a
sign of greater honesty, or of lower standards?

Are you sure that Q-tec is a step above no-names? This picture of

the

insides of their 550W model:

www.bit-tech.net/images/review/123/7.jpg

Makes i seem more like a decent 250W.


5 Va.c. _________\|____ 1 k ohm ___________________ 5 V out
/| | |
diode | |
1000 uF 5V zener
|________|
|
gnd

should provide 5v regulated with a 600 or more peak power output
rating. Depends only on the quality of the capacitor. Maybe I
should go into business.

600 or more _what_?


I'm assuming he meant watts,

"Peak" watts.

but...


Where do you get 5VAC?


More importantly, if he did mean watts, I'd like to see how it'll
get
through that 1k resistor


Easy. It charges the capacitor back up, over time.

There is no time factor in watts.

 

[Watson A.Name - \"Watt Su]

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n25idktp74128@corp.supernews.com...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10mvdnhjiksdf1@corp.supernews.com...

JW wrote:


On Fri, 15 Oct 2004 01:52:52 -0700 "Watson A.Name - \"Watt Sun, the

Dark

Remover\"" <NOSPAM@dslextreme.com> wrote in Message id:
10mv4q1pn2vcv29@corp.supernews.com>:



"CBFalconer" <cbfalconer@yahoo.com> wrote in message
news:416F7B74.E4EAAB68@yahoo.com...


larrymoencurly wrote:


"Chip" <anneonymouse@virgin.net> wrote in message:



"Qtec" - for example - are a very popular low-end brand. You
might refer to them as a no-name, but arguably they are one
step
up from that. They produce a very popular 550w PSU.

The first thing to note is that by 550w, they mean *Peak*.
Which
basically means nothing at all.

I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power. Is it a
sign of greater honesty, or of lower standards?

Are you sure that Q-tec is a step above no-names? This picture
of

the


insides of their 550W model:

www.bit-tech.net/images/review/123/7.jpg


Makes i seem more like a decent 250W.


5 Va.c. _________\|____ 1 k ohm ___________________ 5 V out
/| | |
diode | |
1000 uF 5V zener
|________|
|
gnd

should provide 5v regulated with a 600 or more peak power output
rating. Depends only on the quality of the capacitor. Maybe I
should go into business.

600 or more _what_?


I'm assuming he meant watts,

"Peak" watts.


but...



Where do you get 5VAC?


More importantly, if he did mean watts, I'd like to see how it'll

get

through that 1k resistor


Easy. It charges the capacitor back up, over time.


There is no time factor in watts.

But there is in charging a capacitor through a fixed resistor.

As a matter of fact, you can't store a single watt in that capacitor.
You might store so many coulombs of charge at a certain voltage, but not
watts.

Wattage is dissipation, and if you put a low resistane across the
charged capacitor to get a lot of current, there would be little
dissipation, even for a short time. To get 600W or 120A at 5VDC, the
resistor would be about .04 ohms, and that is probably not much more
than the ESR of the capacitor.

 

[David Maynard]

Franklin wrote:

"Qtec" - for example - are a very popular low-end

brand. You might refer to them as a no-name, but arguably they
are one step up from that. They produce a very popular 550w
PSU.

The first thing to note is that by 550w, they mean *Peak*.
Which basically means nothing at all.




On 15 Oct 2004, larrymoencurly wrote:

I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power.


Does anyone have any 'real' specs for this PSU? You know what I
mean, the normal sort of data in a chart.

I can't find any at their website. I am overlooking a small but
significant link?

I never found anything 'real' on their site either. The only thing I came
up with earlier (but don't have handy) was a customer 'review' on a site
selling them and he claimed to have received an email from them, and posted
the data. The best recollection I have is that the 'real' numbers were 20
to 40% less, depending on the power rail, than the amps put on the sticker.

http://www.qtec.info/products/group.htm?pc=POWER-SUPPLY-UNITS





Is it a
sign of greater honesty, or of lower standards?

Are you sure that Q-tec is a step above no-names? This picture
of the insides of their 550W model:
www.bit-tech.net/images/review/123/7.jpg Makes i seem more like
a decent 250W.

 

[David Maynard]

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n25idktp74128@corp.supernews.com...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10mvdnhjiksdf1@corp.supernews.com...

JW wrote:

On Fri, 15 Oct 2004 01:52:52 -0700 "Watson A.Name - \"Watt Sun, the

Dark

Remover\"" <NOSPAM@dslextreme.com> wrote in Message id:
10mv4q1pn2vcv29@corp.supernews.com>:

"CBFalconer" <cbfalconer@yahoo.com> wrote in message
news:416F7B74.E4EAAB68@yahoo.com...

larrymoencurly wrote:

"Chip" <anneonymouse@virgin.net> wrote in message:

"Qtec" - for example - are a very popular low-end brand. You
might refer to them as a no-name, but arguably they are one

step

up from that. They produce a very popular 550w PSU.

The first thing to note is that by 550w, they mean *Peak*.

Which

basically means nothing at all.

I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power. Is it a
sign of greater honesty, or of lower standards?

Are you sure that Q-tec is a step above no-names? This picture

of

the

insides of their 550W model:

www.bit-tech.net/images/review/123/7.jpg

Makes i seem more like a decent 250W.


5 Va.c. _________\|____ 1 k ohm ___________________ 5 V out
/| | |
diode | |
1000 uF 5V zener
|________|
|
gnd

should provide 5v regulated with a 600 or more peak power output
rating. Depends only on the quality of the capacitor. Maybe I
should go into business.

600 or more _what_?


I'm assuming he meant watts,

"Peak" watts.

but...

Where do you get 5VAC?

More importantly, if he did mean watts, I'd like to see how it'll

get

through that 1k resistor

Easy. It charges the capacitor back up, over time.

There is no time factor in watts.

But there is in charging a capacitor through a fixed resistor.

As a matter of fact, you can't store a single watt in that capacitor.
You might store so many coulombs of charge at a certain voltage, but not
watts.

I didn't say anything about 'storing watts'. The operative word was "time."
As in "there is no time factor in" ... "but there is in."

Wattage is dissipation, and if you put a low resistane across the
charged capacitor to get a lot of current, there would be little
dissipation, even for a short time.

Correct. A real SHORT period of time. But for that short period of time you
could hit '600 watts', under the right conditions.

Then a lot longer to charge the cap back up before you could get another
jolt of "600 peak watts." But, by golly, you can get "600 peak watts" out
of it.

To get 600W or 120A at 5VDC, the
resistor would be about .04 ohms, and that is probably not much more
than the ESR of the capacitor.

You've missed the whole point of his demonstration diagram. The context was
Qtec rating their PSU with "peak watts" and he's showing, with an absurd
circuit, that a "peak power" rating means absolutely nothing except,
perhaps, that it has a low impedance output.

 

[kony]

On Sat, 16 Oct 2004 14:20:17 +0100, Franklin
<no_thanks@mail.com> wrote:

On 14 Oct 2004, kony wrote:

Is there a significant variation in voltages/current required?

Is any such variation mainly due to the design of the mobo? Or
is it mainly due to the choice of components (chipset and
processor)?

Any/all of these can vary current. One board may default
memory to different voltage, another may be running at
higher FSB speed, then the obvious things like chipset or
processor count too... these differences could offset each
other or add up to a signficant difference in some cases.
Even so, the difference between one motherboard and another
will often be much less than the difference between one CPU
or another (if large enough frequency or voltage, core
change), or comparing a budget video card to a high-end
model, or number of hard drives.


Which compenents in a PC tend to use the +3.3V supply? Is it
*typically* the cpu, mobo and memory?

Not CPU. Motherboard may, memory might, but those too can
use 5V, depends on particular manufacturer's design.

 

[Chip]

"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com> wrote
in message news:10n28gk1276j1eb@corp.supernews.com...

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n25idktp74128@corp.supernews.com...
Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10mvdnhjiksdf1@corp.supernews.com...

JW wrote:


On Fri, 15 Oct 2004 01:52:52 -0700 "Watson A.Name - \"Watt Sun, the

Dark

Remover\"" <NOSPAM@dslextreme.com> wrote in Message id:
10mv4q1pn2vcv29@corp.supernews.com>:



"CBFalconer" <cbfalconer@yahoo.com> wrote in message
news:416F7B74.E4EAAB68@yahoo.com...


larrymoencurly wrote:


"Chip" <anneonymouse@virgin.net> wrote in message:



"Qtec" - for example - are a very popular low-end brand. You
might refer to them as a no-name, but arguably they are one
step
up from that. They produce a very popular 550w PSU.

The first thing to note is that by 550w, they mean *Peak*.
Which
basically means nothing at all.

I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power. Is it a
sign of greater honesty, or of lower standards?

Are you sure that Q-tec is a step above no-names? This picture
of

the


insides of their 550W model:

www.bit-tech.net/images/review/123/7.jpg


Makes i seem more like a decent 250W.


5 Va.c. _________\|____ 1 k ohm ___________________ 5 V out
/| | |
diode | |
1000 uF 5V zener
|________|
|
gnd

should provide 5v regulated with a 600 or more peak power output
rating. Depends only on the quality of the capacitor. Maybe I
should go into business.

600 or more _what_?


I'm assuming he meant watts,

"Peak" watts.


but...



Where do you get 5VAC?


More importantly, if he did mean watts, I'd like to see how it'll

get

through that 1k resistor


Easy. It charges the capacitor back up, over time.


There is no time factor in watts.

But there is in charging a capacitor through a fixed resistor.

As a matter of fact, you can't store a single watt in that capacitor.
You might store so many coulombs of charge at a certain voltage, but not
watts.

Wattage is dissipation, and if you put a low resistane across the
charged capacitor to get a lot of current, there would be little
dissipation, even for a short time. To get 600W or 120A at 5VDC, the
resistor would be about .04 ohms, and that is probably not much more
than the ESR of the capacitor.

Ever seen an electronic flash on a camera?

Hint: the flash is *very* short in duration.

Chip

 

[Chip]

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n294b89g4ph62@corp.supernews.com...

Franklin wrote:

"Qtec" - for example - are a very popular low-end
brand. You might refer to them as a no-name, but arguably they
are one step up from that. They produce a very popular 550w
PSU.
The first thing to note is that by 550w, they mean *Peak*. Which
basically means nothing at all.




On 15 Oct 2004, larrymoencurly wrote:

I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power.


Does anyone have any 'real' specs for this PSU? You know what I mean,
the normal sort of data in a chart. I can't find any at their website.
I am overlooking a small but significant link?

I never found anything 'real' on their site either. The only thing I came
up with earlier (but don't have handy) was a customer 'review' on a site
selling them and he claimed to have received an email from them, and
posted the data. The best recollection I have is that the 'real' numbers
were 20 to 40% less, depending on the power rail, than the amps put on the
sticker.

I found this:

http://www.bit-tech.net/images/review/123/5.jpg

 

[David Maynard]

Chip wrote:

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n294b89g4ph62@corp.supernews.com...

Franklin wrote:


"Qtec" - for example - are a very popular low-end

brand. You might refer to them as a no-name, but arguably they
are one step up from that. They produce a very popular 550w
PSU.
The first thing to note is that by 550w, they mean *Peak*. Which
basically means nothing at all.




On 15 Oct 2004, larrymoencurly wrote:


I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power.


Does anyone have any 'real' specs for this PSU? You know what I mean,
the normal sort of data in a chart. I can't find any at their website.
I am overlooking a small but significant link?

I never found anything 'real' on their site either. The only thing I came
up with earlier (but don't have handy) was a customer 'review' on a site
selling them and he claimed to have received an email from them, and
posted the data. The best recollection I have is that the 'real' numbers
were 20 to 40% less, depending on the power rail, than the amps put on the
sticker.



I found this:

http://www.bit-tech.net/images/review/123/5.jpg

Ah. So they put both on the label. ok.

 

[Mike Tomlinson]

In article <755e968a.0410141829.41bea6b5@posting.google.com>,
larrymoencurly <larrymoencurly@my-deja.com> writes

Are you sure that Q-tec is a step above no-names? This picture of the
insides of their 550W model: www.bit-tech.net/images/review/123/7.jpg

That is nasty, isn't it? Take a look inside a Fortron Source (Sparkle)
power supply and compare it with that pic.

Makes i seem more like a decent 250W.

agreed. and that's without the LED fans...

--
..sigmonster on vacation

 

[David Maynard]

Chip wrote:

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n3k1osh82u7f3@corp.supernews.com...

Chip wrote:


"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n294b89g4ph62@corp.supernews.com...


Franklin wrote:



"Qtec" - for example - are a very popular low-end


brand. You might refer to them as a no-name, but arguably they
are one step up from that. They produce a very popular 550w
PSU.
The first thing to note is that by 550w, they mean *Peak*. Which
basically means nothing at all.




On 15 Oct 2004, larrymoencurly wrote:



I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power.


Does anyone have any 'real' specs for this PSU? You know what I mean,
the normal sort of data in a chart. I can't find any at their website.
I am overlooking a small but significant link?

I never found anything 'real' on their site either. The only thing I came
up with earlier (but don't have handy) was a customer 'review' on a site
selling them and he claimed to have received an email from them, and
posted the data. The best recollection I have is that the 'real' numbers
were 20 to 40% less, depending on the power rail, than the amps put on
the sticker.



I found this:

http://www.bit-tech.net/images/review/123/5.jpg

Ah. So they put both on the label. ok.


"OK"? Well sort of. The idea that you have a "550W" PSU with a maximum 12V
supply of 14A I would say is "sharp practise" at best, and fraud at worst.

Chip

I didn't mean it was an 'OK' practice. I was acknowledging the correction
to my (mis)understanding that the real amps were less than what was on the
sticker.

 

[Chip]

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n6m0k8c5h3b50@corp.supernews.com...

Chip wrote:

"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n3k1osh82u7f3@corp.supernews.com...

Chip wrote:


"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n294b89g4ph62@corp.supernews.com...


Franklin wrote:



"Qtec" - for example - are a very popular low-end


brand. You might refer to them as a no-name, but arguably they
are one step up from that. They produce a very popular 550w
PSU.
The first thing to note is that by 550w, they mean *Peak*. Which
basically means nothing at all.




On 15 Oct 2004, larrymoencurly wrote:



I didn't believe it until I visited their website. This has got
to be the first time that a company has admitted that its most
prominently advertised power rating was for peak power.


Does anyone have any 'real' specs for this PSU? You know what I mean,
the normal sort of data in a chart. I can't find any at their
website. I am overlooking a small but significant link?

I never found anything 'real' on their site either. The only thing I
came up with earlier (but don't have handy) was a customer 'review' on
a site selling them and he claimed to have received an email from them,
and posted the data. The best recollection I have is that the 'real'
numbers were 20 to 40% less, depending on the power rail, than the amps
put on the sticker.



I found this:

http://www.bit-tech.net/images/review/123/5.jpg

Ah. So they put both on the label. ok.


"OK"? Well sort of. The idea that you have a "550W" PSU with a maximum
12V supply of 14A I would say is "sharp practise" at best, and fraud at
worst.

Chip

I didn't mean it was an 'OK' practice. I was acknowledging the correction
to my (mis)understanding that the real amps were less than what was on the
sticker.

Oh I see. Sorry for the misunderstanding!

Chip
>

 

[Ken]

LASERandDVDfan wrote:

1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.



I don't think there is anything more to add.
As you said in a fantastically detailed fashion, it is likely a problem in the
drive electronics which has made one or more critical components thermal
sensitive.

What is important now is determining how the drive sustained such damage to
allow this condition in the first place.

For instance, if it was the result of an overheating problem in the computer
itself, this would be an issue that requires effective ventilation to prevent
it from occuring again. - Reinhart

Thanks to all who replied. One thing I did NOT mention in my original
post was that I had acquired an identical HD with the same firmware so
that if the logic board was the cause of failure, I could get the data
off the disk. Swapping out the logic board did not improve the
situation. My reason for suspecting the logic board was that the HD
appeared not to get up to speed fast enough. Upon powering up the HD,
the computer bios would NOT initially detect it. If I did a warm reboot
while still powered up, it would detect the drive as being present on
the second attempt. This logic board swap DID NOT improve the ability
to read the drive, but I thought the motor drive might not be getting
the disk up to the proper RPM's fast enough. When this did not solve my
problem, I went into desperation mode and froze the drive.

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.

 

[Ken]

t.hoehler wrote:

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


Last time I opened a bad hard drive, there was an IC right on the flex
ribbon that goes to the heads. If that is the read / write amplifier, that's
one component you cannot swap out by changing the pcb. Maybe it was a
thermal problem in that IC. Since you have recovered the data, tear the
cover off that bad boy and take a look see.
Regards,
Tom

I have already done so, and I did not see anything that could be
construed as a bad solder connection. After having listened to all the
postings so far, I tend to lean in the direction of the temperature
having an impact on the conductivity of the IC you mentioned. However,
I am still open to theories as to what the impact of cold has on a HD.
What I think is happening, is that the reading of the disk is improved
by the fact that some analog signals that would not reach the level of
the read amplifier are now accepted where they would not be if at a
lower temp. Just a theory however.

 

[Ken]

t.hoehler wrote:

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


Last time I opened a bad hard drive, there was an IC right on the flex
ribbon that goes to the heads. If that is the read / write amplifier, that's
one component you cannot swap out by changing the pcb. Maybe it was a
thermal problem in that IC. Since you have recovered the data, tear the
cover off that bad boy and take a look see.
Regards,
Tom


I have already done so, and I did not see anything that could be

construed as a bad solder connection. After having listened to all the
postings so far, I tend to lean in the direction of the temperature
having an impact on the conductivity of the IC you mentioned. However,
I am still open to theories as to what the impact of cold has on a HD.
What I think is happening, is that the reading of the disk is improved
by the fact that some analog signals that would not reach the level of
the read amplifier are now accepted where they would not be if at a
higher temp. Just a theory however.

 

[Mike Kennedy]

example how it could get out of alignment.. Say the bearings started to
loosen up or say the read head that is glued on to the metal arm loosens up
and moves very slightly.. A hdd is a very precision instrument, it doens't
take much to mess one up.


"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:vnhln0p90qfleaar6ukchjjas62t0mtiqv@4ax.com...

On Sat, 23 Oct 2004 16:50:56 GMT, "Mike Kennedy"
mikek400@R3MOVE.earthlink.net> put finger to keyboard and composed:

It could be a mechanical problem. Have you ever taken apart a hdd? The
read
head is very small and very sensitive. The drive has to compensate for
heating and cooling off in normal operation. If it didnt, it wouldnt work
once the drive started to heat up. I think it may have gotten a out of
alginment from getting too hot and freezing it was just enough to get it
back inside specs.

Modern HDDs use an embedded servo, so I can't understand how alignment
could be an issue.

- Mike

"Ken" <user@domain.invalid> wrote in message
news:QOsed.750782$Gx4.671534@bgtnsc04-news.ops.worldnet.att.net...
LASERandDVDfan wrote:
1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.



I don't think there is anything more to add.
As you said in a fantastically detailed fashion, it is likely a
problem
in the
drive electronics which has made one or more critical components
thermal
sensitive.

What is important now is determining how the drive sustained such
damage
to
allow this condition in the first place.

For instance, if it was the result of an overheating problem in the
computer
itself, this would be an issue that requires effective ventilation to
prevent
it from occuring again. - Reinhart

Thanks to all who replied. One thing I did NOT mention in my original
post was that I had acquired an identical HD with the same firmware so
that if the logic board was the cause of failure, I could get the data
off the disk. Swapping out the logic board did not improve the
situation. My reason for suspecting the logic board was that the HD
appeared not to get up to speed fast enough. Upon powering up the HD,
the computer bios would NOT initially detect it. If I did a warm
reboot
while still powered up, it would detect the drive as being present on
the second attempt. This logic board swap DID NOT improve the ability
to read the drive, but I thought the motor drive might not be getting
the disk up to the proper RPM's fast enough. When this did not solve
my
problem, I went into desperation mode and froze the drive.

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could
be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


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- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

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[Watson A.Name - \"Watt Su]

"Gene the Skeptic" <private@email.000> wrote in message
news:KD8fd.9850$6q2.436@newssvr14.news.prodigy.com...

After 5 years of good service, my ALT-217 monitor is "displaying"
sporadically (~ 2 to 3 times daily) the following problems:
1. Out of the blue, the power-on reset circuit gets triggered and the
monitor
switches off, then turns on by itself. Sometimes after that, all is
well for
a few hours, sometimes goes into a unending cycle. When this happens,
if I
turn the power off and wait a few minutes to turn it on, everything is
fine.
2. Sometimes when 1. happens, the screen adjustments are reset and I
have to
readjust the size & position, vertical & horizontal.
Has anybody any experience with this monitor? Where can I find
schematics?
Any suggestions? BTW I am an EE.
Thanks,
Gene
P.S.
1. I have already posted the message on sci.electronics.repair, but no
replies
2. Searched the web with zero results.
3. Searched the newsgroups, again, with zero results.

I would clean all the air gap spark arrestors, to make sure one of those
isn't arcing. Then I would check the pins of the power supply
connectors for micro cracks in the solder, use a 10x magifier if
necessary. If you find a loose one, remove the solder and wrap some 24
gauge wire around the pin and extend it out along the trace, and
resolder. You'd be surprised at how many pieces of equipment go bye-bye
because of this problem.

If this doesn't cure it and you have something else wrong, you might try
some freeze spray to see if it's a thermal problem. Re-xposting to SER.

 

[Team Goon]

The idiot who was whining about top posting.
Top posting is the deault.

"Chaos Master" <fallenchaos@mailinator.com> wrote in message
news:MPG.1ba18c31a5f60e7a9897c9@news.individual.net...

In an ADM3A terminal, Team Goon typed:
Another stupid old troll has to rear it's ugly head.

Huh?


--
Chaos MasterŽ, posting from Brazil. REPLY TO GROUP!
"People told me I can't dress like a fairy.
I say, I'm in a rock band and I can do what the hell I want!"
-- Amy Lee

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