PSU blown. Why?

G

Grumps

Hi, my PC's been working fine for 3 months; went to it this morning,
pressed the on button, nothing happened.
Took lid off - no motherboard lights on. Swapped power cable,
switched mains on and PHUTT from PSU. Smells a bit horrible. What
can cause this? I guess its a duff PSU but its only 3 months old and
its an expensive Antec unit. Could a short of another component have
caused this?
Problem is as I don't have a spare PSU I won't know what the problem
is until I get the Antec fixed. Is it worth buying a cheap PSU,
unplug all the motherboard components and trying the cheap psu first?
Cheers
 
P

Phisherman

Hi, my PC's been working fine for 3 months; went to it this morning,
pressed the on button, nothing happened.
Took lid off - no motherboard lights on. Swapped power cable,
switched mains on and PHUTT from PSU. Smells a bit horrible. What
can cause this? I guess its a duff PSU but its only 3 months old and
its an expensive Antec unit. Could a short of another component have
caused this?
Problem is as I don't have a spare PSU I won't know what the problem
is until I get the Antec fixed. Is it worth buying a cheap PSU,
unplug all the motherboard components and trying the cheap psu first?
Cheers


Swapping out the PSU with a spare is what I'd do until Antec can honor
their warranty.
 
L

larry moe 'n curly

Grumps said:
Hi, my PC's been working fine for 3 months; went to it this morning,
pressed the on button, nothing happened.
Took lid off - no motherboard lights on. Swapped power cable,
switched mains on and PHUTT from PSU. Smells a bit horrible. What
can cause this? I guess its a duff PSU but its only 3 months old and
its an expensive Antec unit. Could a short of another component have
caused this?
Problem is as I don't have a spare PSU I won't know what the problem
is until I get the Antec fixed. Is it worth buying a cheap PSU,
unplug all the motherboard components and trying the cheap psu first?

PSUs are supposed to be able to stand direct shorts, and the Antec
SmartPowers I've accidentally shorted never seemed to suffer.

Antec gets its PSUs from two manufacturers, Seasonic and Channel Well
Technology, and the latter has been producing the less reliable Antecs
because they contain lower quality electrolytic capacitors that don't
like high heat caused by the slow-spinning fans used. Do a search for
"Fuhjyyu syndrome" to see what I mean". Places like HardOCP.com,
BadCaps.net, ARStechnica.com, JonnyGuru.com, and OverClockers.com have
more information, and an Antec employee who goes by AntecRep hangs out
in some of their forums.. He said that there were problems caused by
the switchover to lead-free solder and one electrolytic cap. in the
+5V standby regulator. The Seasonic-made Antecs, like EarthWatts,
NeoHE (not Neo), and Trio, have been reliable.

I'd buy an inexpensive PSU but not a cheap, shoddily-made one because
there's probably more variation in PSU quality than in the quality of
any other device in a PC. Generally PSUs made by Fortron-Source
(Sparkle, Fortron, Hi-Q, PowerQ) are very good but are among the
cheapest. I believe they make Antec's Basic series.
PS. had a lightning storm the other day; could this have caused it?

Yes, especially in the high voltage section.
 
E

Ed Medlin

Grumps said:
Hi, my PC's been working fine for 3 months; went to it this morning,
pressed the on button, nothing happened.
Took lid off - no motherboard lights on. Swapped power cable,
switched mains on and PHUTT from PSU. Smells a bit horrible. What
can cause this? I guess its a duff PSU but its only 3 months old and
its an expensive Antec unit. Could a short of another component have
caused this?
Problem is as I don't have a spare PSU I won't know what the problem
is until I get the Antec fixed. Is it worth buying a cheap PSU,
unplug all the motherboard components and trying the cheap psu first?
Cheers

It is possible that the storm could have done something, but more that
likely the PSU just died. There have been some problems with Antecs lately
and I am not sure why.


Ed
 
F

Frank McCoy

In alt.comp.hardware.pc-homebuilt larry moe 'n curly
PSUs are supposed to be able to stand direct shorts, and the Antec
SmartPowers I've accidentally shorted never seemed to suffer.
They're *supposed* to.
They have shutdown circuits that are supposed to protect them.
I had an ATI video-card *really* short out bad on me one time.
I mean really *really* REALLY bad.

My first suspicion of trouble was that the PSU was bad, since the whole
system was completely dead and not the slightest flicker of light when
powering up.
It was ... bad.
It failed to even power up my cheapie PSU tester with the lights.
I replaced it temporarily with a "known good" PSU, as a check.
Immediate shutdown!
At least *that* indicated that:
A. There was some kind of short on the computer itself.
B. The original PSU was now bad because of the short.
So ... I investigated further by pulling ALL boards out.
I then found it was the video-board that had crapped all over
everything.
As a (rather stupid) check or verifying, I stuck the bad card in another
(working) computer; figuring the protection on that PSU would save
everything if the board was truly shorted.
The motherboard saved the PSU by blowing a trace ... AFTER which the PSU
finally shut down.
Luckily I was able to find, see, and replace the blown trace on the
motherboard.

OK ... So I got a new and much better video-board.
For some reason it took *three* tries before the new system would power
up properly. But it did; and my main computer was running again.
Also, after putting back the original video-card on the other computer,
it also ran just fine.

.... For about a week.
Then my main computer, the one with the new video-card in it, crapped
out completely. A test with the PSU-tester showed a dead power-supply.
It seems the temporary short when trying to find out if it was
power-supply or short had weakened the PSU so it failed within a week.

Guess what?
Three days later, so did the PSU on the other test computer.

THREE different power-supplies sent to the scrap-heap by one shorted
video-card! (Also, a motherboard *almost* scrapped.)

BTW: All three power-supplies were completely different makes, ratings,
and models; 350, 400, and 550 watt supplies. It was the 550 watt supply
that creamed the motherboard.

So don't trust a PSU to stand up to shorts.
They're *supposed* to; but that's a different story.

Somehow I suspect that actual TESTING power-supplies by shorting them
out just isn't one of the things they do at the manufacturing plant.

If one "survives" for a few minutes after short in design-verification,
then they ass-u-me that the design is OK. ;-{
 
B

BillL

Ed Medlin said:
It is possible that the storm could have done something, but more that
likely the PSU just died. There have been some problems with Antecs lately
and I am not sure why.


Ed

Had an Antec PSU (True Power 500 I think it was) fail on me the other month
(only 8 months or so old). The really worrying bit is had fumes/smoke
exhausting from the back and hadn't shut down!

Using a Coolermaster 600 watt now and hope its going to be more reliable!

BillL
 
S

SteveH

BillL said:
Had an Antec PSU (True Power 500 I think it was) fail on me the other
month (only 8 months or so old). The really worrying bit is had
fumes/smoke exhausting from the back and hadn't shut down!

Using a Coolermaster 600 watt now and hope its going to be more
reliable!
BillL

I've had 4 Antecs go bad n just over a year.

SteveH
 
B

businessman

Ian
PS. had a lightning storm the other day; could this have caused it?

Yes, Yes, and Yes !!!!

Lightning is one of the biggest causes of computer failures.

I always keep my entire computer plugged into a power strip (every
component). When there is a storm, I shut off the strip. That way,
nothing is connected to the line. I unplug the modem phone line too.
 
B

businessman

Hi, my PC's been working fine for 3 months; went to it this morning,
pressed the on button, nothing happened.

By the way, I forgot to mention. If you can smell a burnt smell, and
can remove the cover without killing your warranty, look inside for a
burnt component. Most likely a diode. It should be obvious.
 

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