Power Supply on its way out?
 

A more accurate method of determining an undersized or
slowly failing power supply is to use the 3.5 digit
multimeter. Measurements made to wires as listed in chart in:
http://www.hardwaresite.net/faqpowersupply.html

An under powered power supply will see voltages drop to or
below limits. If critical power supply voltages (3.3, 5, and
12) are in the lower quarter of acceptable limits, then the
power supply may be slowly failing - ie electrolytic filter
capacitors are starting to fail.

Using a meter in combination with what ric has posted can
also demonstrate an under powered or slowly failing supply.
Take voltage measurements. Then power down and remove from
power unessential components such as sound card, extra disk
drives, modem, etc. If voltage returns to limits of that
chart, then power supply is probably running on its maximum
edge - either because it was undersized or because it is
slowly failing. There is no quicker tool to answer your
question than that so inexpensive 3.5 digit multimeter. Tool
so ubiquitous and inexpensive as to be sold in Sears, Home
Depot, Radio Shack, etc. Tool that is essential to reliable
computer maintenance.

Nick wrote:

Sometimes when I switch my PC on it switches off after about 1 second. When
I do it again it works as normal. Is this a sign the power supply is about
to burn out?

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Nick

higher? Im on 300 Watt

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Nick
"ric" wrote in message ...
Nick wrote:

Sometimes when I switch my PC on it switches off after about 1 second.
When
I do it again it works as normal. Is this a sign the power supply is
about
to burn out?

Not necessarily. Could be it is underpowered and one output trips its OC
protection circuit sometimes. That would be my guess with no further info.

Try disconnecting the PSU from unused components and see if the problem
goes away. If so, you need a higher powered PSU.

Nick wrote:

higher? Im on 300 Watt

So what? If your +12v, for example, is only rated at 10 amps, and you need
11 amps at start up, you might need more power on the +12v. Total power
doesn't mean squat if an individual output is under powered.

Nick wrote:

Sometimes when I switch my PC on it switches off after about 1 second.
When
I do it again it works as normal. Is this a sign the power supply is
about
to burn out?

Not necessarily. Could be it is underpowered and one output trips its OC
protection circuit sometimes. That would be my guess with no further info.

Try disconnecting the PSU from unused components and see if the problem
goes away. If so, you need a higher powered PSU.

--
Better than hearing "Lady Day", or checking in at Monterey...

On Wed, 30 Jul 2003 20:32:29 +0000 (UTC), "Nick"
wrote:


Sometimes when I switch my PC on it switches off after about 1 second.
When I do it again it works as normal.
Is this a sign the power supply is about to burn out?

Not necessarily. Could be it is underpowered and one output trips its OC
protection circuit sometimes. That would be my guess with no further info.
Try disconnecting the PSU from unused components and see if the problem
goes away. If so, you need a higher powered PSU.

higher? Im on 300 Watt

Today 300 Watt is to low in many cases.
When starting the PC need a lot more power than normal.
Important is how many ampere it can handle
on every rail +3.3V +5V +12V
http://w1.857.telia.com/~u85710476/d...u_antec550.png
Note: Going up from 300W to 550W power supply does NOT
raise your power consumtion. That is only what the PSU
kan deliver if needed.

ok I'll get rid of the old 4GB HDD just in case

--
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Nick
"Ken" wrote in message
...
On Wed, 30 Jul 2003 20:32:29 +0000 (UTC), "Nick"
wrote:


Sometimes when I switch my PC on it switches off after about 1 second.
When I do it again it works as normal.
Is this a sign the power supply is about to burn out?

Not necessarily. Could be it is underpowered and one output trips its
OC
protection circuit sometimes. That would be my guess with no further
info.
Try disconnecting the PSU from unused components and see if the problem
goes away. If so, you need a higher powered PSU.

higher? Im on 300 Watt

Today 300 Watt is to low in many cases.
When starting the PC need a lot more power than normal.
Important is how many ampere it can handle
on every rail +3.3V +5V +12V
http://w1.857.telia.com/~u85710476/d...u_antec550.png
Note: Going up from 300W to 550W power supply does NOT
raise your power consumtion. That is only what the PSU
kan deliver if needed.

300 watts is up to the task in most cases. However many 300
watt power supplies are sold on price rather than on value and
abilities. Many 300 watt supplies may not even supply 300
watts. And many who repair computers don't even know why
failure happens - they just use the Tim Allen concept of 'more
power' and assume that solved the problem. This demonstrates
why the problem may be even more complex:
http://firingsquad.gamers.com/guides/power/default.asp

Get the meter and stop guessing. If power is a problem,
then the meter will show it up front and immediate. You can
spend your life wildly trying this and that. Or save time,
read the numbers, and isolate the problem - immediate and
obvious.

Chances are if the system was working just fine previously
and if nothing was added, then 300 watts was more than
sufficient. Currently, there is not even one good, reliable,
known number to work with - to provide a solution. No number
means junk science. Get the meter. See if the power supply
really is a problem - rather than guessing.

Nick wrote:
ok I'll get rid of the old 4GB HDD just in case

--
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Nick