lsmartino wrote
Rod Speed wrote
Well, it can be estimated how long will a power semiconductor
run if you leave it without a proper heatsink.
Not in a domestic environment it aint, because
the ambient temperature varys so much.
I got a bit of a start relatively recently when someone was having
overheating problems with their PC to discover that they were one
of the few in this area who were silly enough to have no form of
cooling whatever, not even a swamp cooler, in an area which can
see 10 days over 40C some summers. We had one just last week
and it got to 44C, and it was like walking into a furnace walking
outside my airconditioned house.
They can do the estimate considering an ambient temperature of 20šC - 25šC.
Pity that is completely useless when determining whether the TV will
survive the warranty period when used at much higher temps than that.
Check the datasheet of any semiconductor
and learn something before you write.
I was doing that likely before you were even born thanks.
Any rise in the temperature will shorten the lifespan of the product.
Wrong when the life is indefinite at any temps that the product will ever see.
To me, thatīs a quite profitable scenario.
Thanks for that completely superfluous proof that you have never ever designed a TV.
Also, you will notice that the same circuit will have electrolytic
capacitors near heat sources, when itīs a well known fact that
heat shortens dramatically the life of electrolytics caps.
In practice that isnt a significant problem with domestic appliances.
Essentially because you dont see many electros in that situation with them.
Are you crazy?
Nope.
Have you ever seen a modern SMPS?
Yep, I may well have been using them since before you were even born too thanks.
Try to tell all us that a SMPS (Switched Mode Power Supply, in case
you donīt know what a SMPS is) donīt HAVE electrolytics caps,
I never ever said anything even remotely resembling anything like that.
and that those caps doesnīt have a finite lifespan.
Or that either.
Even electrolytics are classified based
on their MBTF at certain temperatures.
Duh.
Again, try to find the datasheet of some electrolitycs caps,
Dont need to, did that likely before you were even born too thanks.
and educate yourself.
Retake Bull****ting 101.
The manufacturer know how to properly design an electronic
circuit in order to provide a long life, but it also it knows how
to design it to fail within a short term under certain conditions,
No they dont on that silly claim about surviving the
warranty fine, but failing immediately after that expires.
No one is telling that the product will explode right after the warranty expires,
Some have run the mindlessly silly line that it can
be designed to fail just after the warranty runs out.
but that it can be designed to fail within a
short life span, especially with cheap products.
Have fun explaining the host of domestic electronic devices that dont.
and accordingly they estimate a warranty just long
enough to cover the product for a safe term, a
safe term for the manufacturer, not the user.
Have fun explaining how come not a single electronic device
I have ever owned has died just after the warranty has run out.
And that includes my latest gigantic widescreen TV too.
Of course itīs impossible to predict exactly how many years
the TV will last, but the manufacturer count with statistical
data which says, for instance, that a TV set is turned on
10 hours per day for instance, and taking that into account,
and estimating how long the weakest part of the TV will last
under these conditions, they can determine the warranty lapse.
Pity about the TVs that get left on all the time.
A TV, or a computer monitor left on all the time will last less time
of course. A CRT has a definite lifespan, and if the monitor or the
TV set is a LCD based one, the CFL bulbs used to light up the screen
have a definite lifespan. Did you knew that, Mr. Know Nothing ?
Corse I did, Master Pathetic Excuse for a Bull**** Artist.
Pity its got nothing to do with your stupid pig ignorant claim
that is possible to design a product to survive the warranty
period and die shortly after that expires, with so much
variation in the detail of how domestic appliances are used.
The claim is completely fanciful and those making that sort of
claim have obviously never actually designed a damned thing.
And only the stupidest manufacturer would deliberatly design
their product to die as soon as the warranty has expired
anyway, because the bulk of those who had bought such
a dud wouldnt be buying another from that manufacturer.
Tell that to the manufacturer of Coby products, for instance.
Dont need to.
They have quite a long time selling trash that fails quite quickly.
Because there are enough who havent been dudded
with a product of theirs to buy a dud of theirs.
Basic mathematics.
They quote the useful lifetime of a hardrive in MTBF hours.
That is calculated, not measured. Convert that MTBF
to years and you will discover why they cant possibility
have tested them to get those numbers.
Donīt answer "itīs impossible" if you are not prepared to give
a real explanation. Samsung, Seagate, WD... any decent hard
drive manufactures gives an estimate lifetime of their products.
These estimates are provided in the datasheet of each harddrive.
And they are ESTIMATES, not measured results.
Exactly, these are estimates,
Pity the claim was about TESTING, which doesnt happen, like I said.
and most of the time very accurate,
Like hell it is. Have you actually tried converting
the MTBF of a current hard drive to years ?
It can be something like 15 years or more of constant use, without a stop.
Its actually a hell of a lot more years than that.
And I have seen hard drives surviving at least more than 10 years of hard work.
Me too. Pity about the years the MTBF turns into.
specially those concerning the maximum number of startups/stops
the drive can tolerate before the heads get completely worn.
Wrong again. Its such a round number it cant have been produced
by TESTING, and the number of starts and stops dont produce
any wear of the heads with modern hard drives anyway.
You are wrong again.
Nope.
When the platters stops, the heads contact the platters.
Not anymore, they are retracted now.
While the platters are spinning at full speed, the heads are separated from
them by a small air cushion formed by the rotational speed of the platter.
Duh.
As soon the HDD is turned off, the platters loses speed, and eventually
the air cushion dissapear, thus the heads make contact with the platters.
No they dont, they are retracted now.
The same happens in reverse sequence when the HDD starts.
Wrong again.
Thatīs why start / stop cicles have a definite impact in any HDD.
Wrong again. Its actually the spinup thats the problem life wise.
Have you ever wondered why a HDD last less in
a home environment than in a office environment?
They dont necessarily.
Check this out http://phorums.com.au/archive/index.php/t-42666.html
No thanks, its just plain wrong on that line about heads landing on the platters now.
It might teach you a thing or two.
Not even possible for you. You're clearly certain you know it all when you clearly dont.
Isnt it time you ran up the white flag ?