Power supply fried, replaced it, computer won't start

Yesterday morning, ten hours after I'd last powered my PC down, I turned
it on and noticed immediately a burning "electrical fire" smell.

Turned the computer off (using Windows shutdown first from the login
screen), disconnected all peripherals and the power, opened the case.
Attached the power cord only, started it, everything worked (hard drives
were cycling, CPU fan going, motherboard lights on, etc.), but I noticed
the smell again. I did some sniffing and it was definitely coming from
the power supply. Then the computer just stopped.

I am not a "hardware guy" but I did some research on the web, consulted
with the friend who helped me build the computer, and it seemed pretty
open and shut. The 350 watt supply that came with the case ($35 for
case and supply) was to blame.

So went to CompUSA today and picked up
http://www.compusa.com/products/prod...ct_code=283768 -
seemed to be a worthy "bang for the buck" 400-watt supply.

http://www.hardwaresecrets.com/article/362/ is the instructions I
followed.

Before disconnecting the old PSU, I carefully labelled every connection,
showing what it was connected to, and the orientation on the drive or
board. (The PSU had a 20-pin connection to the motherboard, the ATX12V
comnnector, and my computer has two hard drives, a DVD drive, and a 3.5"
floppy.)

Plugged the computer in, turned on the PSU, and nothing. Ultimately, I
tried a known good power cord and the new cord that came with the PSU, a
known working outlet, several permutations, nothing. The voltage
selector is correct (115 volts) on the back of the PSU. When I apply
power, the CPU fan turns for about two seconds then stops (no harsh or
unusual noises - it was turning fine yesterday). The green light on the
motherboard stays lit. But no drive lights come on, and no sign of any
activity.

I don't have a multimeter. I'm not an electrician or electrical
engineer. I just want some suggestions on what might be wrong and how
to fix it. FWIW, the motherboard seems to show no abuse; the capacitors
all look shiny and intact.

My friend who built the PC for me is traveling, and I will ultimately
bring the computer to him and his extensive testbench if I can't figure
this out myself. But I'm really at my wit's end now and am hoping for a
few useful "try this" suggestions.

.. wrote:

Yesterday morning, ten hours after I'd last powered my PC down, I
turned it on and noticed immediately a burning "electrical fire" smell.

Turned the computer off (using Windows shutdown first from the login
screen), disconnected all peripherals and the power, opened the case.
Attached the power cord only, started it, everything worked (hard
drives were cycling, CPU fan going, motherboard lights on, etc.), but
I noticed the smell again. I did some sniffing and it was definitely
coming from the power supply. Then the computer just stopped.

I am not a "hardware guy" but I did some research on the web,
consulted with the friend who helped me build the computer, and
it seemed pretty open and shut. The 350 watt supply that came
with the case ($35 for case and supply) was to blame.

So went to CompUSA today and picked up
http://www.compusa.com/products/prod...ct_code=283768 -
seemed to be a worthy "bang for the buck" 400-watt supply.

http://www.hardwaresecrets.com/article/362/ is the instructions I followed.

Before disconnecting the old PSU, I carefully labelled every
connection, showing what it was connected to, and the orientation on
the drive or board. (The PSU had a 20-pin connection to the
motherboard, the ATX12V comnnector, and my computer has two hard
drives, a DVD drive, and a 3.5" floppy.)

Plugged the computer in, turned on the PSU, and nothing. Ultimately,
I tried a known good power cord and the new cord that came with the
PSU, a known working outlet, several permutations, nothing. The
voltage selector is correct (115 volts) on the back of the PSU. When
I apply power, the CPU fan turns for about two seconds then stops

That usually indicates that the motherboard has decided
there is a major problem, so it shuts down very quickly.

(no harsh or unusual noises - it was turning fine yesterday).
The green light on the motherboard stays lit.

That is just the +5VSB, standby voltage.

But no drive lights come on, and no sign of any activity.

I don't have a multimeter. I'm not an electrician or electrical
engineer. I just want some suggestions on what might be wrong

Likely something got killed when the original power supply died.

and how to fix it.

Unplug everything except the motherboard
and see if the cpu fan comes on and stays on.

If it does, plug the hard drive in and see if it will boot
with just the motherboard and hard drive connected etc.

FWIW, the motherboard seems to show no abuse;
the capacitors all look shiny and intact.

The tops should be flat.

My friend who built the PC for me is traveling, and I will ultimately
bring the computer to him and his extensive testbench if I can't
figure this out myself. But I'm really at my wit's end now and am
hoping for a few useful "try this" suggestions.

.. wrote:

unusual noises - it was turning fine yesterday). The green light on the
motherboard stays lit. But no drive lights come on, and no sign of any
activity.

http://www.bootdisk.com/bootlist/275.htm#4

"." wrote in message
...
Yesterday morning, ten hours after I'd last powered my PC down, I turned
it on and noticed immediately a burning "electrical fire" smell.

Turned the computer off (using Windows shutdown first from the login
screen), disconnected all peripherals and the power, opened the case.
Attached the power cord only, started it, everything worked (hard drives
were cycling, CPU fan going, motherboard lights on, etc.), but I noticed
the smell again. I did some sniffing and it was definitely coming from
the power supply. Then the computer just stopped.

I am not a "hardware guy" but I did some research on the web, consulted
with the friend who helped me build the computer, and it seemed pretty
open and shut. The 350 watt supply that came with the case ($35 for
case and supply) was to blame.

So went to CompUSA today and picked up
http://www.compusa.com/products/prod...ct_code=283768 -
seemed to be a worthy "bang for the buck" 400-watt supply.

http://www.hardwaresecrets.com/article/362/ is the instructions I
followed.

Before disconnecting the old PSU, I carefully labelled every connection,
showing what it was connected to, and the orientation on the drive or
board. (The PSU had a 20-pin connection to the motherboard, the ATX12V
comnnector, and my computer has two hard drives, a DVD drive, and a 3.5"
floppy.)

Plugged the computer in, turned on the PSU, and nothing. Ultimately, I
tried a known good power cord and the new cord that came with the PSU, a
known working outlet, several permutations, nothing. The voltage
selector is correct (115 volts) on the back of the PSU. When I apply
power, the CPU fan turns for about two seconds then stops (no harsh or
unusual noises - it was turning fine yesterday). The green light on the
motherboard stays lit. But no drive lights come on, and no sign of any
activity.

I don't have a multimeter. I'm not an electrician or electrical
engineer. I just want some suggestions on what might be wrong and how
to fix it. FWIW, the motherboard seems to show no abuse; the capacitors
all look shiny and intact.

My friend who built the PC for me is traveling, and I will ultimately
bring the computer to him and his extensive testbench if I can't figure
this out myself. But I'm really at my wit's end now and am hoping for a
few useful "try this" suggestions.

Poor quality power supplies have two very nasty habits:

1) They die early (that is GUARANTEED, btw), often shortly after leaving
the factory
2) With no built-in component protection, they often take other components
with them, when they die. In other words, cheap power supplies kill
motherboards, hard drives, CPUs, RAM, etc.

Your post is about TWO poor quality power supplies. I suspect that the
first one died ungracefully, taking the motherboard out with it. The second
one can't even power itself, apparently.

It's your money, but people don't seem to understand that often spending an
extra 40 bucks or so on a GOOD power supply can save a complete rebuild,
costing hundreds of bucks. -Dave

On Sun, 27 Aug 2006 23:30:02 GMT, "." wrote:

Yesterday morning, ten hours after I'd last powered my PC down, I turned
it on and noticed immediately a burning "electrical fire" smell.

Turned the computer off (using Windows shutdown first from the login
screen), disconnected all peripherals and the power, opened the case.
Attached the power cord only, started it, everything worked (hard drives
were cycling, CPU fan going, motherboard lights on, etc.), but I noticed
the smell again. I did some sniffing and it was definitely coming from
the power supply. Then the computer just stopped.

I am not a "hardware guy" but I did some research on the web, consulted
with the friend who helped me build the computer, and it seemed pretty
open and shut. The 350 watt supply that came with the case ($35 for
case and supply) was to blame.

So went to CompUSA today and picked up
http://www.compusa.com/products/prod...ct_code=283768 -
seemed to be a worthy "bang for the buck" 400-watt supply.

http://www.hardwaresecrets.com/article/362/ is the instructions I
followed.

Before disconnecting the old PSU, I carefully labelled every connection,
showing what it was connected to, and the orientation on the drive or
board. (The PSU had a 20-pin connection to the motherboard, the ATX12V
comnnector, and my computer has two hard drives, a DVD drive, and a 3.5"
floppy.)

Plugged the computer in, turned on the PSU, and nothing. Ultimately, I
tried a known good power cord and the new cord that came with the PSU, a
known working outlet, several permutations, nothing. The voltage
selector is correct (115 volts) on the back of the PSU. When I apply
power, the CPU fan turns for about two seconds then stops (no harsh or
unusual noises - it was turning fine yesterday). The green light on the
motherboard stays lit. But no drive lights come on, and no sign of any
activity.

I don't have a multimeter. I'm not an electrician or electrical
engineer. I just want some suggestions on what might be wrong and how
to fix it. FWIW, the motherboard seems to show no abuse; the capacitors
all look shiny and intact.

My friend who built the PC for me is traveling, and I will ultimately
bring the computer to him and his extensive testbench if I can't figure
this out myself. But I'm really at my wit's end now and am hoping for a
few useful "try this" suggestions.

If all you hook up to the power supply is the MOBO (no RAM or CPU) and
you can't even get to post (a beep, no beeps at all) then your problem
is probably (98%) a fried MOBO. Just hope it didn't go any further.

"Dave C." wrote:

Poor quality power supplies have two very nasty habits:

1) They die early (that is GUARANTEED, btw), often shortly after leaving
the factory
2) With no built-in component protection, they often take other components
with them, when they die. In other words, cheap power supplies kill
motherboards, hard drives, CPUs, RAM, etc.

Your post is about TWO poor quality power supplies. I suspect that the
first one died ungracefully, taking the motherboard out with it. The second
one can't even power itself, apparently.

It's your money, but people don't seem to understand that often spending an
extra 40 bucks or so on a GOOD power supply can save a complete rebuild,
costing hundreds of bucks. -Dave

I knew better, I did, but I had a spare mother board; bought a case
and Power supply duo for $50 - the sheet metal of the case was so thin
just tightning the screws would strip it out.

It lasted about three weeks, or the first power fluctuation - Lost the
power supply and mother board.

Just agreeing with you, One should not scrimp on the power supply, buy
the best.


--
Board Dots
http://www.boredmuch.com/view.php?id=764

Lookout wrote:

If all you hook up to the power supply is the MOBO (no RAM or CPU) and
you can't even get to post (a beep, no beeps at all) then your problem
is probably (98%) a fried MOBO. Just hope it didn't go any further.

There are generally two things that cause a major smell when they burn
out:

1. Monitor
2. The Case Power Supply

The case power supply can, tho rare, also take out other parts in a
system when it goes bad or burns.


--
http://www.bootdisk.com/

On Sun, 27 Aug 2006 23:30:02 GMT, "." wrote:

Yesterday morning, ten hours after I'd last powered my PC down, I turned
it on and noticed immediately a burning "electrical fire" smell.

Turned the computer off (using Windows shutdown first from the login
screen), disconnected all peripherals and the power, opened the case.
Attached the power cord only, started it, everything worked (hard drives
were cycling, CPU fan going, motherboard lights on, etc.), but I noticed
the smell again. I did some sniffing and it was definitely coming from
the power supply. Then the computer just stopped.

I am not a "hardware guy" but I did some research on the web, consulted
with the friend who helped me build the computer, and it seemed pretty
open and shut. The 350 watt supply that came with the case ($35 for
case and supply) was to blame.

So went to CompUSA today and picked up
http://www.compusa.com/products/prod...ct_code=283768 -
seemed to be a worthy "bang for the buck" 400-watt supply.

http://www.hardwaresecrets.com/article/362/ is the instructions I
followed.

Before disconnecting the old PSU, I carefully labelled every connection,
showing what it was connected to, and the orientation on the drive or
board. (The PSU had a 20-pin connection to the motherboard, the ATX12V
comnnector, and my computer has two hard drives, a DVD drive, and a 3.5"
floppy.)

Plugged the computer in, turned on the PSU, and nothing. Ultimately, I
tried a known good power cord and the new cord that came with the PSU, a
known working outlet, several permutations, nothing. The voltage
selector is correct (115 volts) on the back of the PSU. When I apply
power, the CPU fan turns for about two seconds then stops (no harsh or
unusual noises - it was turning fine yesterday). The green light on the
motherboard stays lit. But no drive lights come on, and no sign of any
activity.

I don't have a multimeter. I'm not an electrician or electrical
engineer. I just want some suggestions on what might be wrong and how
to fix it. FWIW, the motherboard seems to show no abuse; the capacitors
all look shiny and intact.

My friend who built the PC for me is traveling, and I will ultimately
bring the computer to him and his extensive testbench if I can't figure
this out myself. But I'm really at my wit's end now and am hoping for a

A name brand supply would be a good start. I don't care how it looks
or how heavy it is; unless it is known working from another system or
an Antec or Enermax, I'd be trying a different one. The first junk
supply could've taken out the mainboard, but we can't tell that yet.

In article ,
"Rod Speed" wrote:

Unplug everything except the motherboard
and see if the cpu fan comes on and stays on.

If it does, plug the hard drive in and see if it will boot
with just the motherboard and hard drive connected etc.

Thanks to you and all who responded.

My original post asserted that I wasn't an engineer. True. But I
solved the problem with your advice above, thinking systematically like
an engineer. I disconnected the power supply and connected everything
one by one, and the computer is now fully functional. From a little
research I did, I think my issue was that I'd connected the 3.5" floppy
power incorrectly or partially.

I also appreciate everyone's point about not being cheap. In 15+ years
of heavy computer use, i've never had a PSU go bad on me. But given all
the heartache this burnout caused, I'll from now on spend the extra
money for an Antec or other name brand supply. If I'd lost something
really important and known that an extra $40-50 would have averted the
disaster, I'd have been kicking myself.

.. wrote
"Rod Speed" wrote

Unplug everything except the motherboard
and see if the cpu fan comes on and stays on.

If it does, plug the hard drive in and see if it will boot
with just the motherboard and hard drive connected etc.

Thanks to you and all who responded.

My original post asserted that I wasn't an engineer. True. But I
solved the problem with your advice above, thinking systematically
like an engineer. I disconnected the power supply and connected
everything one by one, and the computer is now fully functional.
From a little research I did, I think my issue was that I'd connected
the 3.5" floppy power incorrectly or partially.

Yeah, it isnt hard to get that on wrong.

I also appreciate everyone's point about not being cheap. In 15+
years of heavy computer use, i've never had a PSU go bad on me.
But given all the heartache this burnout caused, I'll from now on spend
the extra money for an Antec or other name brand supply. If I'd lost
something really important and known that an extra $40-50 would have
averted the disaster, I'd have been kicking myself.

You'd be a lot better off with full backups of everything that
matters, any power supply can die. Hard drives in spades.