replacing power supply

[Charlie Brookhart]

I currently have a 250W power supply in my system. I am thinking about
wanting to upgrade the video card in my system to a ATI 9800 PRO. It is my
understanding that there will need to be a bigger power supply in order to
handle this video card. Is changing out the power supply something that is
easy to do? The only thing I have done inside the case is remove and replace
the system cards as well as add memory modules. I don't have any experience
with the power supply. Will the pins from the new power supply fit onto the
main connection pin on the motherboard or will I have to get a new
motherboard?

 

[Daniel Barkho]

I currently have a 250W power supply in my system. I am thinking about
wanting to upgrade the video card in my system to a ATI 9800 PRO. It is my
understanding that there will need to be a bigger power supply in order to
handle this video card. Is changing out the power supply something that is
easy to do? The only thing I have done inside the case is remove and replace
the system cards as well as add memory modules. I don't have any experience
with the power supply. Will the pins from the new power supply fit onto the
main connection pin on the motherboard or will I have to get a new
motherboard?

Changing the power supply is very simple. 250W is fairly low, especially
if you will be adding power hungry equipment into the PC.

You will not need a new motherboard. PSU's are pretty much one size fits
all so to speak.

If you find it hard, make a note of where the plugs from the old PSU go
before you put in the new one. If you get stuck you can just refer to
that. You will generally have 2 plugs going into the motherboard, and
the others into the hardware (V/C, HDD etc)

 

[kony]

I currently have a 250W power supply in my system. I am thinking about
wanting to upgrade the video card in my system to a ATI 9800 PRO. It is my
understanding that there will need to be a bigger power supply in order to
handle this video card.

Almost certainly yes, you should upgrade it.

Is changing out the power supply something that is
easy to do?

Yes, unplug all the plugs, unscrew 4 or 5 screws, then do
the opposite with the new one. Rarely you'll find the rear
switch for AC voltage needs changed to your location, so
check that too.

The only thing I have done inside the case is remove and replace
the system cards as well as add memory modules. I don't have any experience
with the power supply. Will the pins from the new power supply fit onto the
main connection pin on the motherboard or will I have to get a new
motherboard?

If you have a standard ATX motherboard (which is very likely
to be planning on a Radeon 9800), not a very, very
proprietary PC-clone or workstation, odds are great it'll
"fit", be compatible. If yoy posted details of your
motherboard make/model (perhaps a link to it online) and
current power supply model, we could confirm that.

Another consideration is cable routing, try to secure cables
out of the way such that there's no chance of one getting
into a fan, and try to use all the cables, not bunching up a
bunch of devices on the same cable until it's necessary.

 

[John]

I currently have a 250W power supply in my system. I am thinking about
wanting to upgrade the video card in my system to a ATI 9800 PRO. It is my
understanding that there will need to be a bigger power supply in order to
handle this video card. Is changing out the power supply something that is
easy to do? The only thing I have done inside the case is remove and replace
the system cards as well as add memory modules. I don't have any experience
with the power supply. Will the pins from the new power supply fit onto the
main connection pin on the motherboard or will I have to get a new
motherboard?

The plugs are standardized and its pretty hard to plug them in wrong
though Ive actually seen posts where some have plugged things in wrong
.. You really have to be determined to plug them in wrong cause they
are shaped to fit in a certain way. Basically you use common sense and
take a close look at the shape of the plugs - if they are angles at a
certain corner etc and fit them in the way they are designed to fit in

The only thing is if you have a 250 watt - is it an AT system or ATX ?
Is it an ancient system or not? Cause if its too old you might as well
spend a bit a get a newer system. If its OK then its generally not
hard at all to swap out the PS except you have to do a lot of plugging
in and out of components.

The other problems is if you have a proprietary case thats unusual in
some way and if you have a dinky case that may not easily accept some
types of PSes. Ive seen an emachines that was OK 2000 XP Athlon that
had a 250 watt PS.

 

[Charlie Brookhart]

I have a Dell Dimmension 8300 Desktop that I purchased in July of 2003. As
far as the systemboard, it is a planar G0728 model according to the system
configuration page at dell.

I have noticed that all the power supplies have an on/off switch in the
back. How does this work when there is an on/off switch in the front of the
computer?

Here is the current system configuration:
Dell Dimension 8300
250W power supply (unsure of the model)
Planar G0728 motherboard (according to configuration page at dell.com)
512MB memory
P4 2.6G

 

[Zotin Khuma]

I currently have a 250W power supply in my system. I am thinking about
wanting to upgrade the video card in my system to a ATI 9800 PRO. It is my
understanding that there will need to be a bigger power supply in order to
handle this video card. Is changing out the power supply something that is
easy to do? The only thing I have done inside the case is remove and replace
the system cards as well as add memory modules. I don't have any experience
with the power supply. Will the pins from the new power supply fit onto the
main connection pin on the motherboard or will I have to get a new
motherboard?

You gave no details about your system that would give a clue about 1)
whether you need a PSU upgrade and 2) how easy it would be to replace
it.

250W is rather low for a modern system, but if it's a good quality
unit and the rest of your system has modest power needs, you may still
get by with 250W. Replacing it with at least a 300W PSU (preferably
more) will ensure that it'll have enough juice to run your system w/o
problems. However, as has often been said before in other threads
here, you can't just take the stated power rating of just any old PSU
at face value. Get a reliable brand.

Replacing a PSU is no more difficult than replacing the cards and
memory modules. You have to remove and refit the screws that fix the
PSU to the case and the various connectors to the motherboard and
other devices. If you have a branded computer with a proprietary
(non-standard) PSU, you'll have to get a suitable unit. Unless you
have a rare proprietary product for which it's impossible to get a
suitable PSU, you won't have to get a new mobo.

 

[John Smithe]

The only thing I have done inside the case is remove and replace
the system cards as well as add memory modules.

You should be fine. The PS isn't any more difficult. As previously stated
you may want to note how the cables are routed now and route them that way
again, just to speed up the process. Just try not to get them too tangled,
don't block fans, airflow, or vents and keep them off heatsinks. Its mostly
just common sense.

To make sure the screw holes match up you can measure yours and check the
spec sheets at the manufacturer sites. I'm talking about spacing and
pattern and not so much screw size. Screw type and size should be the same.
Look for a mechanical drawing of the candidate PS's. This might be overkill
but this will ensure that if Dell did something non-standard you won't get
bit. Also measure the physical size of your power supply for an idea if the
new one will fit in your case.

I have noticed that all the power supplies have an on/off switch in
the back. How does this work when there is an on/off switch in the
front of the computer?

The switch in the back, on the power supply itself, switches AC power to
the supply itself. If this switch is 'OFF', then your PC cannot be turned
on. If the PS switch is 'ON' then the PC, using the front panel switch and
power-management software/firmware, control what happens. The switch on the
front of the PC is monitored by circiuts on the motherboard. These
circuits, along with power management software/firmware control turn-on,
standy-by, turn-off, and possibly other functions of your PC. Check out the
Power Management applet in Control Panel for an idea of what I am babbling
about. Yes, this does mean that if the PS is plugged in and the PS switch
is on that part of the motherboard is receiving power. There is a '5volt
standby supply', +5vstby or something like that, to provide this power to
the motherboard.

Here is the current system configuration:
Dell Dimension 8300
250W power supply (unsure of the model)
Planar G0728 motherboard (according to configuration page at dell.com)
512MB memory
P4 2.6G

Check the video card manufacturer site to determine the new video cards'
power requirements. Video card manufacturers frequently recommend a minimum
PS power rating for their newer cards.

For long term upgradability look for a supply with a separate 4-pin
connector for the CPU. Just in case you upgrade your motherboard later.
Newer motherboards use these 4-pin connectors. Adaptors are available so
its not absolutely necessary. Also possibly look for a supply with power
connectors for SATA if you think SATA hard drives are in your future.
Lastly look for lots of 12volt amps. I have seen recommendations for a
minimum of 20Amps (20A) on the 12volt supply. This is because newer
motherboards power the CPU from the 12v supply. Video cards may also do
this, I am not sure.

good Luck

 

[Charlie Brookhart]

Here is a link that I received from Dell support that has all the
information about the power supply. It appears that it is in fact a 250W
PSU. As far as the systemboard, this is how Dell describes it:
Dell ELX "flat" standard based on the Intel Canterwood (875)P chipset. It
uses the Canterwood (875)P Memory Controller Hub (MCH), the I/O Controller
Hub (ICH5), and Intel Pentium 4 (P4) processors.

Here is the link:

http://support.dell.com/support/edocs/systems/dim8300/sm/techov.htm#1102452

 

[kony]

Here is a link that I received from Dell support that has all the
information about the power supply. It appears that it is in fact a 250W
PSU. As far as the systemboard, this is how Dell describes it:
Dell ELX "flat" standard based on the Intel Canterwood (875)P chipset. It
uses the Canterwood (875)P Memory Controller Hub (MCH), the I/O Controller
Hub (ICH5), and Intel Pentium 4 (P4) processors.

Here is the link:

http://support.dell.com/support/edocs/systems/dim8300/sm/techov.htm#1102452

That linked power supply is electrically a
connector-compatible standard ATX power supply. The problem
is that it appears to be a unique form-factor, different
from standard ATX, but not mATX either. The picture might
be deceiving, it might be a mATX-L (mATX that mounts on the
long side) but if the picture's semi-accurate then it
appears to be wider than an mATX, which would make sense as
typically only overrated mATX are called "250W", generally
their casing is too small to afford over 200W output.

You might measure the available space your case has in the
PSU mounting area, the mounting holes used to secure the
power supply, then compare to the following dimensions (in
mm).
http://www.pcpowerandcooling.com/products/power_supplies/dimensions/dimensions.htm

 

[Charlie Brookhart]

According to Dell, size does not matter. I talked to them about this
particular issue as far as what size the current psu is and how it might be
different from the standard sizes. They assured me that this was not a
problem, but they are probably leading me in the wrong direction. I will try
the most recent suggestion listed and see what I get out of that.

That linked power supply is electrically a
connector-compatible standard ATX power supply. The problem
is that it appears to be a unique form-factor, different
from standard ATX, but not mATX either. The picture might
be deceiving, it might be a mATX-L (mATX that mounts on the
long side) but if the picture's semi-accurate then it
appears to be wider than an mATX, which would make sense as
typically only overrated mATX are called "250W", generally
their casing is too small to afford over 200W output.

You might measure the available space your case has in the
PSU mounting area, the mounting holes used to secure the
power supply, then compare to the following dimensions (in
mm).

http://www.pcpowerandcooling.com/products/power_supplies/dimensions/dimensions.htm