Computer won't turn on, power supply squeals

  • Thread starter Thread starter Ben
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Ben

We have a PC that's a component of a much bigger system. The system
uses European-style power (it was made in France), so the computer's
power supply must be set to 230 volts. After some recent maintenance,
someone forgot to set the PC back to 230 when putting it back into the
system. The user turned it on, heard some loud pops, and unplugged it.
I was called in to help from there.

The power supply smelled like smoke, so I replaced it. When plugged
in, the power supply makes a very high-pitched noise and the computer
won't turn on at all. I tried replacing the processor, memory, video
card and unplugging everything else, but this did not fix the problem.
I replaced the motherboard, no dice. I have tried two other power
supplies, another processor, different memory, etc. Basically,
everything that's hooked up in the system is new, but the power supply
still whines and the system won't boot. The power supply only makes
the noise when the main power connector to the system board is
attached.

The system is a Dell XPS R450 with an Intel P2 processor (yes, it's
rather old). Some documentation: http://support.dell.com/support/edocs/systems/dkhan/

I'd really appreciate any suggestions anyone might have.

Thank you,

Ben
 
Ben said:
We have a PC that's a component of a much bigger system. The system
uses European-style power (it was made in France), so the computer's
power supply must be set to 230 volts. After some recent maintenance,
someone forgot to set the PC back to 230 when putting it back into the
system. The user turned it on, heard some loud pops, and unplugged it.
I was called in to help from there.

The power supply smelled like smoke, so I replaced it. When plugged
in, the power supply makes a very high-pitched noise and the computer
won't turn on at all. I tried replacing the processor, memory, video
card and unplugging everything else, but this did not fix the problem.
I replaced the motherboard, no dice. I have tried two other power
supplies, another processor, different memory, etc. Basically,
everything that's hooked up in the system is new, but the power supply
still whines and the system won't boot. The power supply only makes
the noise when the main power connector to the system board is
attached.

The system is a Dell XPS R450 with an Intel P2 processor (yes, it's
rather old). Some documentation: http://support.dell.com/support/edocs/systems/dkhan/

I'd really appreciate any suggestions anyone might have.

Thank you,

Ben
Click to expand...
Welcome to the world of older Dells. That machine uses a NON standard
supply wiring. It is NOT ATX, but rather the 3.3 volts is supplied
through a separate connector. Figure 2.5 of the reference and
troubleshooting guide shows this.
I was unable to locate the proper wiring at the XPS R docs, but the XPS
T docs do show it. Check the color codes of the original supply against
the, which are found here;
http://support.dell.com/support/edocs/systems/dkub/techovu.htm#dc_power_connector_pin_assignments
 
We have a PC that's a component of a much bigger system. The system
uses European-style power (it was made in France), so the computer's
power supply must be set to 230 volts. After some recent maintenance,
someone forgot to set the PC back to 230 when putting it back into the
system. The user turned it on, heard some loud pops, and unplugged it.
I was called in to help from there.

The power supply smelled like smoke, so I replaced it. When plugged
in, the power supply makes a very high-pitched noise and the computer
won't turn on at all. I tried replacing the processor, memory, video
card and unplugging everything else, but this did not fix the problem.
I replaced the motherboard, no dice. I have tried two other power
supplies, another processor, different memory, etc. Basically,
everything that's hooked up in the system is new, but the power supply
still whines and the system won't boot. The power supply only makes
the noise when the main power connector to the system board is
attached.

The system is a Dell XPS R450 with an Intel P2 processor (yes, it's
rather old). Some documentation: http://support.dell.com/support/edocs/systems/dkhan/

I'd really appreciate any suggestions anyone might have.
Click to expand...


As Pen mentioned you probably have a system that requires a
proprietary Dell PSU. You might find one on the 'net or
through Dell, or you might consider having the original
repaired (or DIY). Primary point of failure was probably
the switching transistors on one of the two heatsinks.
 
kony said:
As Pen mentioned you probably have a system that requires a
proprietary Dell PSU. You might find one on the 'net or
through Dell, or you might consider having the original
repaired (or DIY). Primary point of failure was probably
the switching transistors on one of the two heatsinks.
Click to expand...
Re Dell parts, you can call or go on line.
You could try Dell parts at
http://warrantypartsdirect.dell.com/us/Program/index.asp
or 1-800-357-3355 Dell spare parts.
 
Ben said:
We have a PC that's a component of a much bigger system. The system
uses European-style power (it was made in France), so the computer's
power supply must be set to 230 volts. After some recent maintenance,
someone forgot to set the PC back to 230 when putting it back into the
system. The user turned it on, heard some loud pops, and unplugged it.
I was called in to help from there.

The power supply smelled like smoke, so I replaced it. When plugged
in, the power supply makes a very high-pitched noise and the computer
won't turn on at all. I tried replacing the processor, memory, video
card and unplugging everything else, but this did not fix the problem.
I replaced the motherboard, no dice. I have tried two other power
supplies, another processor, different memory, etc. Basically,
everything that's hooked up in the system is new, but the power supply
still whines and the system won't boot. The power supply only makes
the noise when the main power connector to the system board is
attached.

The system is a Dell XPS R450 with an Intel P2 processor (yes, it's
rather old). Some documentation:
http://support.dell.com/support/edocs/systems/dkhan/

I'd really appreciate any suggestions anyone might have.

Thank you,

Ben
Click to expand...


Ben

Depending on your luck when a power supply is blown up like this, the down
stream effects can range from nothing (ie replace the supply and all is
well) to all manner of parts fried/spiked.

The whining sound usually indicates the power supply is trying to supply
current outside it's ratings and going into a shutdown restart cyle at the
'whining' frequency'
This overload current could well be caused by fried components in any one of
the parts of the PC or something as simple as a loose screw shorting
something out.

As Pen and Kony have pointed out that model Dell usually requires a 'Dell'
specific power supply.

If you used a suitable Dell replacement power supply then the symptoms you
described suggest there were more fried components in the original
motherboard/cpu/ram/hd/fdd/video card (etc) as a result of the overvoltage.
Subsequent connection of good parts to damaged parts may well have fried
some of the new good components.

If you replaced it with a standard ATX supply there is regretfully a good
chance you have simply complicated the situation.

May I suggest the most productive course of action would be to write the
Dell off and tell the owner/user to 'go get a new one'.
Then treat all the parts that have been installed in that PC as suspect and
auction them off as damaged goods.


Best
Paul.
 
We have a PC that's a component of a much bigger system. The system
uses European-style power (it was made in France), so the computer's
power supply must be set to 230 volts. After some recent maintenance,
someone forgot to set the PC back to 230 when putting it back into the
system. The user turned it on, heard some loud pops, and unplugged it.
I was called in to help from there.

The power supply smelled like smoke, so I replaced it. When plugged
in, the power supply makes a very high-pitched noise and the computer
won't turn on at all. I tried replacing the processor, memory, video
card and unplugging everything else, but this did not fix the problem.
I replaced the motherboard, no dice. I have tried two other power
supplies, another processor, different memory, etc. Basically,
everything that's hooked up in the system is new, but the power supply
still whines and the system won't boot. The power supply only makes
the noise when the main power connector to the system board is
attached.

The system is a Dell XPS R450 with an Intel P2 processor (yes, it's
rather old). Some documentation:http://support.dell.com/support/edocs/systems/dkhan/

I'd really appreciate any suggestions anyone might have.

Thank you,

Ben
Click to expand...


To clarify a bit on what others have said:

The p2 and p3 dells have a propriatary power supply. BUT any power
supply pulled from a p2 or p3 dell should work.

And it is possible to adapt a standard atx PSU to the dell computer.

http://pinouts.ru/Power/dell_atxpower_pinout.shtml
http://pinouts.ru/Power/dell_atxaux_pinout.shtml
 
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