HP-d3057f3r power supply. Computer won't turn on. The green light on the power supple comes on but when the ATX 24 pin power computer is plugged into the the mother board, the green light dims out. Pulled all expansion cards, memory, and unplugged all cables, fans and drives and still ave the same issue. When I unplug the ATX cable, the green light is birght. Can't determine if its the power supply or the motherboard. Did pulled the CPU and had the same results. Any ideals?

Take the power supply to a retailer or computer shop in your local area to be tested. Pretty standard from what I have found out.
Bestec ATX 300 12Z Rev DDR Replacement Power Supply HP 5188 2625 Have a great day.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/william_02fc2766c1e13b73

Your computer, Dell Dimension E521 Desktop PC, will not turn on, and someone told you the problem is the motherboard?

Unless you stated to this entity, that you spotted leaking Electrolytic Capacitors on the motherboard, how can they assume this?

I believe you should check whether the problem is the Power On switch, or the Power Supply.

1) The Power On switch is located inside the plastic Power On button. It is an ATX power on switch. (The Power On switch is a Momentary Contact Switch )

This is an example of an ATX power on switch, that I have found fits many desktop computers,

http://www.directron.com/atxswitch.html

The test to perform bypasses the Power On switch. It does NOT involve the Power On switch itself, however.

Bypassing the Power On switch turns the computer (Power Supply) on?
Problem is the Power On switch.

Bypassing the Power On switch does NOT turn the computer (Power Supply) on?
The problem is the Power Supply.

A) Computer on a table, computer unplugged from power, computer case open.
I would then lay the computer on it's side, on a towel, on the table, computer case opening UP.
Watch the cables attached to the computer.

This is so you can access the components inside of the computer more easily. This will become apparent in a moment.
Now follow Anti-Static Precautions.

Anti-Static Precautions:
Your body carries Static electricity. Static WILL fry out (Short Circuit) the delicate hardware components inside a computer.
Relieve your body of Static BEFORE reaching inside the computer.

(Have to restate) Computer on a table, computer unplugged from power, computer case open.
TOUCH an unpainted surface, of the metal frame of the open computer case.
This action will relieve your body of Static.

Should you leave your computer in the middle of working on it, (For ANY reason), be SURE to touch the metal frame again upon your return.

Now you are safe, and the computer is safe. Let's begin;

Inside your computer there is a power cable coming from the Power Supply, that plugs into the motherboard. This power cable I'm referring to is the 24-pin ATX main power cable.

This is an example of a 24-pin ATX main power cable, and it's respective connector on the motherboard,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

Female connector on motherboard shown in the Left photo.
Power cable connector shown in the middle photo.

The photo to the right shows the ATX main power cable plugged into the motherboard.
This is how it needs to be for the test. It also shows the color of the various wires going into it.
We only need to be concerned with Two wires.

The Green wire, and ANY Black wire.

The Green wire is the Soft Power On wire. It is also abbreviated as PS_ON.
ANY Black wire you see is a Ground wire.

A jumper wire is used to BRIEFLY connect the Green wire, to ANY Black wire.
(Again, the Power On switch is a Momentary Contact Switch)

The jumper wire preferred to use is a paper clip. The paper clip is straightened out, then bent into a U-shape.
Look at the U-shape upside down. The top/middle is wrapped a few times with black plastic electrical tape. This is for your fingers, and thumb to hold onto.

The 'legs' of the U-shape go down into the Back of the ATX main power cable's connector.
(I shortened 24-pin ATX main power cable to ATX main power cable)

Look at the photo to the right. See how the Green wire goes down into a squarish socket hole?
Look at the photo in the middle. See the metal tube shapes at the Front of the connector?
Brass looking, slightly square?

These are metal terminals. There is a metal terminal for every wire, going down into the ATX main power cable connector.

The 'leg' of the U-shape jumper wire goes down into the Back of the connector (ATX main power cable connector), RIGHT NEXT TO the existing wire that is in the socket hole.

It has to go down into the squarish socket hole far enough, to pass by the insulation of the wire, and Touch the metal terminal.

Example:
One leg of the U-shape goes down into the socket hole of the Green wire, right next to the Green wire, and touches the metal terminal.

The other leg of the U-shape goes down into a socket hole, with ANY Black wire, and touches the metal terminal pin.

The leg MUST touch the metal terminal pin.

The contact made is brief. No more than 2 seconds. (1001,..1002)

Shock warning. None.
The Soft Power On wire (Green wire) has 5 Volts DC going through it.
In comparison two D cell flashlight batteries produce 3 Volts DC.

HOWEVER, there may be a spark, as both legs of the U-shape jumper wire touch their respective metal terminals. Warning you in advance.

You are also holding onto the black plastic electrical tape. (One wrap of black plastic electrical tape will insulate you from 600 Volts DC)

IF, the jumper wire turns the computer on, (Power Supply actually), the problem is a bad Power On switch.

IF, the jumper wire does Not turn the computer on, the problem is a bad Power Supply.

The Power Supply used in a Dell Dimension E521 Desktop PC, is an ATX (Form Factor) power supply.

The form factor ATX for a Power Supply refers to the size, and shape of the Power Supply's case, and the power cables provided with the Power Supply.

The size, and shape of the ATX power supply case is approximately 6 inches Wide (Width), 5-1/2 inches Long (Length), and 3-1/2 inches Tall. (Height)

With the power cables offered with today's offering of ATX power supply's, there is no need to be concerned if the ATX power supply in question, has the needed power cables.

ATX power supply's sold now, have the correct power cables you'll need, and the correct amount of power cables.

This is just one example of an ATX power supply that will work,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1389575&CatId=1078

Scroll down to the bold heading - Detailed Features
Look at the chart under the subheading - Connectors

Note the first connector shown. This is a 20-pin plus a 4-pin main power cable.
Both power cables are used for your 24-pin ATX main power cable connector, on your motherboard.

This gives a little more information on a 20 + 4-pin ATX main power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20plus4

Note the photo to the right. This particular motherboard has a 20-pin ATX main power cable connector. It does not require the additional 4-pin power cable.
Yours does.

Do Not confuse the 4-pin ATX +12 Volt power cable, with the 4-pin power cable that comes with a 20 + 4-pin ATX main power cable.

The 4-pin power cable you need is in the harness of wires, for the 20 + 4-pin ATX main power cable.

There WILL be a 4-pin ATX +12 Volt power cable, however. This is an example of a 4-pin ATX +12 Volt power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4

(Color of the connectors for any power cable, does Not matter. They can be any color)

Dell Support > Dimension E521 Desktop PC > Service Manual,

http://support.dell.com/support/edocs/systems/dime521/en/SM_EN/index.htm

In the list click on - Technical Overview
Now click on - System Board Components

22 is where the 24-pin ATX main power cable plugs in.

(NOTE*
The 24-pin ATX main power cable connector, and the 4-pin ATX +12 Volt power cable connector, have a Lock on the side. The plastic rectangle on the side of the connector/s.
This Lock has a hook on the bottom end. The end that faces the motherboard.
The hook goes over a Tab on the female connector, on the motherboard.

The Lock acts like a see-saw on a playground. The top of the Lock is squeezed in. This action brings the hooked end away, from the Tab on the motherboard female connector.
Then the power cable CONNECTOR is wiggled, and removed from the female motherboard connector.

{ ONLY use the Connector when removing it. DO NOT pull on the wires)

2 points to where the 4-pin ATX +12 Volt power cable plugs in.
That's it for the Power Supply power cables.

1 points to where the Processor Fan plugs into.
5 and 6, point to where the Data cables from the SATA harddrive, and SATA optical drives, plug into.
(This is if the Dimension E521 has SATA optical drives, and not IDE { PATA} optical drives)

[ The SATA data cable connector has 7 contact pins in it. It is the shorter connector.
The SATA power cable has 15 pins in it. It is the longer connector.

IF, the SATA harddrive has a provision for using a SATA power cable, AND a 4-pin Peripheral power cable (Mislabeled as Molex), ONLY use just the SATA power cable. Otherwise the SATA harddrive will burn out. Sometimes not right away, but eventually it does ]

Going back to the main page for the Service Manual, click on -
Removing and Installing Parts.

Removing the Computer Cover is listed, as well as Power Supply.

For additional questions please post in a Comment.

Regards,
joecoolvette

The Green LED light flashing indicates a bad Power Supply. Weak voltage power rail.

http://h10025.www1.hp.com/ewfrf/wc/product?product=404643&lc=en&cc=us&dlc=en&submit.y=7&submit.x=7&lang=en&cc=us

Troubleshooting Power Supply Issues HP Pavilion A520n,

http://h10025.www1.hp.com/ewfrf/wc/document?docname=bph06788&tmp_task=solveCategory&lc=en&dlc=en&cc=us&site=null&lang=en&key=null&product=404643#N207

Click on > Power Supply light is on or flashes

"If the LED is still flashing (it should not flash with all connectors removed), plug the power cable into a different power outlet that is known to be good. If the LED still flashes, the power supply should be replaced."


Cause?
The leading cause is the computer is dirty inside, to include the Power Supply
The next cause is that Electrolytic Capacitors have failed inside the Power Supply.

Solution is to replace the Power Supply.

The Power Supply used is the ATX form factor. The type of Power Supply used in over 80 percent of PC computers out there, and very readily available.

Size of the power supply case is approximately 6 inches Wide, 5-1/2 inches long (5.5), and 3-1/2 inches Tall. (3.5)

It is a 250, or 300 Watt generic unit, probably made by Bestec, Delta, or HiPro.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00072236&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&lang=en&product=404643

Scroll down to see the illustration and photo of the motherboard.

Power cables needed are;

A) 20-pin ATX main power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20

{ ATX power supply's today come with a 20 + 4-pin ATX main power cable.
The power cable can be used as a 20-pin, or a 24-pin.

Add the 4-pin connector to make it a 24-pin, or do not use it, and have a 20-pin }


B) Enough standard 4-pin Peripheral power cables for the IDE (PATA) harddive, {1}, and the optical drive/s.

http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral

Today's power supply's come with either at least 4, or 6 of these power cables.

C) One Floppy Drive power cable.
Won't be used for a Floppy Disk Drive on your computer. It's power for the Memory Card Reader.

http://www.playtool.com/pages/psuconnectors/connectors.html#floppy


All of the above power cables are typical when purchasing an ATX power supply today.
Need guidance in choosing a Power Supply, please state in a Comment.

Regards,
joecoolvette

Bad Power Supply.
Weak voltage power rail, or rails.
{There are three voltage power rails.
1) The 3.3 Volt power rail
2) The 5 Volt power rail
3) The 12 Volt power rail}

The flashing Green LED light is one direct indication of this for HP computers.
Usually there is at least enough power to light LED lights, and spin fans, but your Power Supply doesn't even have that much power.

1) All of the LED lights on at once use less than 1 Watt of power
2) EACH fan uses 2 to 3 Watts of power
3) A typical Processor can use 51 to 125 Watts of power.
Depends on what Processor it is.

The HP Pavilion A847C desktop computer has an ATX power supply, with a maximum rated wattage of 250 Watts.

The ATX form factor for a Power Supply refers to it's case size, for one.
5-1/2 inches Long, 3-1/2 inches Tall, and 6 inches Wide
The common type of Power Supply used in over 80 percent of PC computers out there, and readily available all over.


HP Support > Pavilion a847c desktop computer > Main support page,

http://h10025.www1.hp.com/ewfrf/wc/product?product=448706&lc=en&cc=us&dlc=en&submit.y=7&submit.x=5&lang=en&cc=us

Click on Product information in the list
Now click on Product specifications

Finally click on > Motherboard Specifications, PTGD1-LA (Goldfish )

Scroll the page down to view the motherboard illustration and photo.


The replacement Power Supply has to have,

A) A 24-pin ATX main power cable.
In the motherboard photo, view the Ram Memory slots. The long Blue, and Black slots.

To the right of the bottom corner of the Black ram slot (Slot 4) is a whitish connector.
Two columns of 12 socket holes.
This is where the 24-pin ATX main power cable plugs into.
(ATX Power Connector in the motherboard illustration)

Typical 24-pin ATX main power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

NOTE the Lock Clip on the side of the connector.


B) 4-pin ATX +12 Volt power cable.
At the bottom Left corner of the Processor socket is a whitish square connector.
4 socket holes.
This is where the 4-pin ATX +12 Volt power cable plugs into.
(ATX12V in the motherboard illustration)

Typical 4-pin ATX +12 Volt power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4

NOTE the Lock Clip on the side of the connector.

{The top of the Lock Clip is squeezed in to release it, and is held while the power cable is removed.
Same for the 24-pin ATX main power cable's connector}


C) SATA power cable.
Used for the SATA harddrive

The SATA power cable has 15 pins, and is the longer connector.
The SATA data cable has 7 pins, and is the shorter connector.

IF, the SATA harddrive has provisions for plugging in a SATA power cable, AND a 4-pin standard Peripheral power cable, ONLY USE the SATA power cable.
Otherwise you will burn up the SATA harddrive.

The SATA power cable plugs into the SATA harddrive.
One end of the SATA data cable plugs into the motherboard, and the other end plugs into the SATA harddrive.

Below the ram slots in the bottom Right corner are the SATA headers on the motherboard, that the SATA harddrive plugs into.
The Blue, Orange, Black and White connectors.

Of course the SATA harddrive only plugs into one of them.
Looking at the motherboard illustration you will see they are numbered.
SATA 1, SATA 2, SATA 3, and SATA 4.

IT DOESN'T MATTER which one you plug your harddrive into. (Or any SATA device)
That's the beauty of SATA.
BIOS will find the harddrive.
But for you, it will be easier to keep track of where the SATA harddrive is plugged in, if you just use SATA 1.

Typical SATA power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#sata


D) 4-pin standard Peripheral power cable.
Commonly referred to as Molex. (Misnomer)

Used for optical drives, Fans, and other associated hardware.

Typical 4-pin standard Peripheral power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral


E) 4-pin Small Peripheral power cable.
Used to be commonly used for a Floppy Drive.
For your computer it provides power to the Memory Card Reader.

Typical 4-pin Small Peripheral power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#floppy

Watch disconnecting, and connecting this connector. You can bend the pins very easily.
SAFETY
WATCH your fingers as the pins are QUITE SHARP!

All of the power cables listed above are standard for today's Power Supply's.

About the Wattage.
A computer ONLY uses the power it needs, and NO more.

If you put a 10,000 Watt power supply in, and the computer only needed 100 watts for what it is doing, it will ONLY use 100 watts.
To wit, if you install a Power Supply with more Wattage than 250 Watts, it will NOT hurt your computer.

If you need guidance in replacing your Power Supply, or recommendations for a Power Supply, please state in a Comment.

Regards,
joecoolvette

(Apologize for being so lengthy)

Bad Power Supply. Weak voltage power rail.

Has enough power to light LED lights, and maybe spin fans, but not enough to turn the Processor on.

1) ALL of the LED lights on at once use less than 1 Watt of power.

2) EACH fan uses 2 to 3 Watts.

3) A typical Processor uses 51 to 125 Watts. Depends on what Processor it is.

The Compaq Presario SR2013WM desktop computer, comes with an AMD Athlon 64 3800+ processor, that fits in a Socket AM2.

1) http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00777760&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&lang=en&product=3300335


Can use up to 62 Watts.

2) http://en.wikipedia.org/wiki/List_of_AMD_Athlon_64_microprocessors#.22Orleans.22_.28F2_.26_F3.2C_90_nm.29

No Processor operating, no computer.
No computer operating, No Signal to the monitor. (No video signal, or also known as No VGA Signal)

The Power Supply used is just one of the common ATX form factor power supply's.
Used in over 80 percent of PC's out there, and readily available.
(ATX size of the power supply case, is approximately 5-1/2 inches Long, 3-1/2 inches Tall, and 6 inches Wide)

It is 250 Watt, and a generic model. Probably made by Bestec, Delta, or HiPro.
(You can use a larger wattage Power Supply with NO problems.
A computer ONLY uses the power it needs, and NO more)

A) The ATX main power cable is a 24-pin ATX main power cable. All of the new power supply's have an ATX main power cable, where the connector can be used as a 20-pin, or 24-pin.

B) Uses a 4-pin ATX +12 Volt power cable.

C) Past the two power cables above, just make sure the Power Supply has a SATA power cable, (For the SATA harddrive), a Floppy Drive power cable, (Used for the Card Reader), and enough 4-pin standard Peripheral power cables.
(Misnomered as 'Molex')


3) Typical 24-pin ATX main power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

4) Typical 4-pin ATX +12 Volt power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4

5) Typical SATA power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#sata

IF, the SATA harddrive has a provision for using a 4-pin standard Peripheral power cable, AND a SATA power cable, ONLY USE THE SATA POWER CABLE.

If you use both you will burn up the SATA harddrive.


6) Typical 4-pin standard Peripheral power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral


Have questions regarding the above, or need recommendations on a Power Supply, please post in a Comment.
Regards,
joecoolvette

Most motherboards now have a 24-pin power supply connector. If you haven't already found a diagram showing the pinouts of the 20- and 24-pin power plugs, here's one borrowed from a handy site:



The two plugs are essentially the same, but the 24-pin version duplicates some voltages on the extra pins. The extra pins in the larger connector were meant to provide extra current paths for voltages that see heavy loads from newer processors and motherboard circuitry. Depending on how a motherboard is designed, it might work with a 20-pin plug connected (leaving pins 11, 12, 23 and 24 empty). But typically if the board has a 24-pin connector it needs the 24-pin power supply plug.

Most power supplies have a 20-pin plug with a separate 4-pin section that fastens to it for connection to a 24-pin mobo connector. It typically has one side designed to slide onto the end of the 20-pin plug, essentially turning it into the 24-pin version. This added plug does not have a retaining clamp on its side, so you can tell it from the the 4-pin CPU power plug. The wire colors are also different. For reference, here is the processor power plug, from the same website:


New motherboard specs call for the separate processor power connector for the same reason the extra pins were added to the power supply connector: to handle the high currents needed by increasingly faster CPUs.

When the motherboard has these connectors, you need to use them all to get everything working. Hope this helps. Thanks to smspowersupply.com for the diagrams, and thank you for using Fixya.

Test whether the problem is the Power On switch, or the Power Supply.

The Power On switch is located inside the plastic Power On button. It's removable in most cases.
This is a typical ATX power on switch,

http://www.directron.com/atxswitch.html

To test you will bypass the Power On switch.

If the Power Supply comes on, you have a bad Power On switch.
If the Power Supply does Not come on, you have a bad Power Supply.

The test doesn't involve the Power On switch, or it's wires.

It involves the 20 or 24-pin ATX main power cable, the Soft Power On wire, (Green), and ANY Ground wire.
(Black)
A jumper wire is used from the Green wire to ANY Black wire.

Computer unplugged from power, observe Anti-Static Precautions, BEFORE you reach inside.

Anti-Static Precautions:
Your body carries Static electricity.
Static will fry out (Short Circuit) the hardware components inside a computer.
Computer unplugged from power, TOUCH the metal frame of the open computer case. Touch an unpainted surface.

This action will relieve your body of Static.
Should you leave your computer in the middle of working on it, be SURE to Touch the metal frame again upon your return.

You may have to ease a few cables over to view the motherboard.
You are looking for the 20, or 24-pin ATX main power cable.
(Don't know if your model uses a 20-pin, or a 24-pin.
This is what you're looking for,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20

Scroll down to see the 24-pin ATX main power cable.
Look at the photo to the far right.
The Green wire is the Soft Power On wire.
ANY Black wire is a Ground wire.

With the ATX power cable plugged into the motherboard, as shown in the photo to the far right, you are going to insert a jumper wire down into the socket holes.

The jumper wire goes down in the socket hole, Right next to the wire that is in the hole.
It goes down in far enough to touch a metal terminal, that is at the end of the wire.
(Approximately 1/2 inch)

The jumper wire of choice is a paper clip straightened out, then bent into a U-shape.
The middle of the U is wrapped a few times with black plastic electrical tape.
(Trivia: One wrap of black plastic electrical tape is enough for 600 Volts DC)

The voltage you will be dealing with is 5 Volts DC.
Two D cell flashlight batteries produce 3 Volts DC.

You may wish to wear a glove on the hand that holds the jumper wire. There may be a small spark.
The Power Supply, (Computer), is plugged into power.

One end of the U-shaped jumper wire, is inserted down into the socket hole with a Green wire. (Right next to the wire)
The other end is inserted down into a socket hole with ANY Black wire.
The contact made is no more than 2 seconds. (1001, 1002)

If the computer comes on, (Power Supply actually), the Power On switch is bad.
If the computer does not come on (Power Supply), the Power Supply is bad.

It IS the Power Supply cjshearer11.

The green LED light flashing is a diagnostic light now. The diagnosis is a bad Power Supply with a Gree LED flashing.

Secondly, notice how the accessories are unplugged, and the Green LED light is solid Green?

1) ALL of the LED lights combined use less than 1 Watt of power.
2) EACH fan uses 2 to 3 Watts

3) A typical Processor can use 51 to 125 Watts. Depends on what Processor it is.

Compaq Presario SR1350NX?
Uses an Intel Pentium 4, Model 519 (LGA 775 processor socket)

3.06GigaHertz maximum frequency rate (3.06GHz 'speed')
533MegaHertz Front Side Bus. (533MHz FSB)
1MegaByte of L2 cache. (1MB L2 cache)
Can use up to 89 Watts,

http://en.wikipedia.org/wiki/List_of_Intel_Pentium_4_microprocessors#Prescott_.2890.C2.A0nm.29

You press the Power On button. Inside the plastic Power On button is a Power On switch.

(Typical ATX power on switch,

http://www.directron.com/atxswitch.html )

The Power On button presses against the Power On switch making a momentary contact.
(The Power On switch is a Momentary Contact Switch)

This closes a circuit temporarily that has 5 volts present. The 5 Volt Standby power.
(The 5 volts is always present when the Power Supply is plugged into power)

The 5 Volts is directed towards a circuit within the Power Supply.
The Soft Power On circuit. (PS_ON)

This in turn 'excites' the Power Supply, and turns the Power Supply on.
(No pun intended)

The first chip on the motherboard to receive power is the BIOS chip.
(Chip and Chipset are slang terms for I.C.
Integrated Circuit)

Burned into the BIOS chip is a small program. The BIOS program.
The BIOS program looks to see what devices are installed, does a Ram Memory count, TURNS the Processor on, and hands the computer over to the Operating System.
(Windows XP, and Windows Vista are two examples of an O/S)

Your Power Supply has a weak voltage power rail.
(There are three main power rails in the SMPS in your Presario computer's Power Supply.
{Switched-Mode Power Supply}
The 3.3 Volt power rail, the 5 volt power rail, and the 12 volt power rail)

Enough power to light LED lights, and maybe spin fans, (Or spin a few times, and stop), but Not enough power to turn the Processor on.
NO Processor operating, no finding the boot record of the Operating System, on the Harddrive.

Do you have a KNOWN to be good, compatible power supply in an unused desktop computer, to use for a test unit?
Someone you may know may have upgraded to a better computer, and have a working computer with a Power Supply that you could borrow.

Needs to be an ATX form factor Power Supply.
Form factor for a Power Supply refers to the size, and shape of the case, for one.
It also applies to the power cables coming out of the power supply.

The size and shape of the case is;
6 inches Wide, 5.5 inches Long, and 3-1/2 inches Tall.

Needs a,
A) 24-pin ATX main power cable,
B) 4-pin ATX +12 Volt power cable,
C) Enough standard 4-pin Peripheral power cables, for the optical drive/s (CD/DVD drive/s),
D) One SATA power cable

A) 24-pin ATX main power cable:

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

B) 4-pin ATX +12 Volt power cable: (Power for the Processor)

http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4

C) SATA power cable: (Power for the SATA Harddrive. 15-pin cable)

http://www.playtool.com/pages/psuconnectors/connectors.html#sata

D) Standard 4-pin Peripheral power cable:

http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral

The ATX power supply inside that Presario, is probably rated at a maximum Wattage of 250 to 300 Watts.
Made by some generic Power Supply manufacturer.
Bestec, HiPro, or Delta.
Around 90 percent of the desktop PC's out there use an ATX Power Supply.
You can buy one with as much Wattage as you want, won't hurt the computer.
A computer ONLY uses the power it needs, and No more.

Regards,
joecoolvette

1) Check to make sure your surge protector has power. Power On LED light is lit.

2) Check THE receptacle, in the surge protector that the computer is plugged into.
I have had a few bad surge protectors where just THAT receptacle was bad.
"Hmmm, surge protector Power On LED light is lit.
Monitor, printer, and router plugged into the surge protector have power."

Plugged a table lamp into THAT receptacle in the surge protector, that the computer was plugged into, found it to be bad.

3) Perform the test to check whether it is a bad Power On switch, or a bad Power Supply.

The Power On switch is located inside the plastic Power On button.
This is a generic Power On switch (ATX), that I have found fits many computers,

http://www.directron.com/atxswitch.html

The test involves bypassing the Power On switch. Has nothing to do with the Power On switch wires.
A jumper wire is used on your 20, or 24-pin ATX main power cable's connector.

The jumper wire goes from the Soft Power On wire, (Also referred to as PS_ON. It is a Green wire), to ANY Black wire in the main power cable's connector.

Since you didn't post what computer you have, (Computer manufacturer, and Model Number), I have to give you generic information.
It may also be, that there is no direct information available for the computer you have.

1) This is a 20-pin ATX main power cable, and it's connector,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20

2 This is a 24-pin ATX main power cable, and it's connector,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

[Older computers use the 20-pin ATX main power cable. Later computers needed more power to the motherboard, hence 4 more power wires were added. 24-pin ATX main power cable ]

Computer unplugged from power, observe Anti-Static Precautions.

[ Anti-Static Precautions:
Your body carries Static electricity.
Static will fry out (Short Circuit) the hardware components inside a computer.

Computer on a table, computer unplugged from power, computer case open; TOUCH the metal frame of the open computer case.
This will relieve your body of Static.

While working on your computer your hands, and forearms should occasionally touch the metal frame.
But if you leave your computer in the middle of working on it, be SURE to Touch the metal frame again upon your return ]

If you bypass the Power On switch, and the computer comes on, (Power Supply comes on), you have a bad Power On switch.

If you bypass the Power On switch, and the computer Does Not come on, (Power Supply), you have a bad Power Supply.

The test is to use a jumper wire on the 20, or 24-pin ATX main power cable's connector.
The jumper wire connects from the Soft Power On wire, (Green), to ANY Ground wire. (ALL Black wires are Ground wires)

The 20, or 24-pin ATX main power cable is plugged into the motherboard.
The Power Supply, (Computer), is plugged into power.

Use one end of a jumper wire, to go down into the socket hole with a Green wire, and the other end of the jumper wire to go down into a socket hole, with ANY Black wire.

The jumper wire must go down into the socket hole pretty far.
The jumper wire goes down into the socket hole, right next to the wire that is already in the socket hole.

The jumper wire has to go down in the socket hole far enough, to touch a metal terminal that is on the end of the wire.
I realize that this may look complicated on 'paper', but I'm just being very detailed.

Most use a jumper wire made from a paper clip. The paper clip's diameter is thin enough to slide down into the socket hole, right next to the wire that is already in the socket hole. (And touch the metal terminal at the bottom of the wire)

The paper clip is straightened out, then bent into a U-shape.
Black plastic electrical tape is wound around the middle of the U-shape.
The taped part is what you hold onto.

The voltage for the Soft Power On wire, (Green) is 5 Volts DC.
Two D cell flashlight batteries produce 3 Volts DC.
Just in case you have reservations.

There may be a spark. Warning you in advance.
You may wish to use a glove, on the hand that holds the jumper wire.
Just make a brief contact with the jumper wire. No more than 2 seconds should suffice.

If the Power Supply comes on, you have a bad Power On switch.
If the Power Supply does not come on, you have a bad Power Supply.
No if's, and's, or but's about it.

Tell me the computer manufacturer name, and model number, and we'll see if a compatible Power Supply can be found.
Post in a Comment.

Suggest you start with checking the receptacle in the surge protector, that the Computer is plugged into.

I have had 3 surge protectors now that just THAT receptacle was bad.

"Hmmm, surge protector LED power on light is lit.
Monitor, printer, and router, plugged into the surge protector have power."
Plugging in a lamp into the receptacle in the surge protector, that the computer was plugged into, proved just THAT receptacle was bad.

Not an issue?

Then I suggest you check to see if the problem is the Power On switch, or the Power Supply.

The Power On switch is located inside the plastic Power On button.
This is an example of a generic ATX Power On switch,

http://www.directron.com/atxswitch.html

The test is to use a jumper wire for the Soft Power On, and bypass the Power On switch.

If the Power Supply comes on, the problem is the Power On switch.
If the Power Supply does Not come on, the problem is the Power Supply.
Bad Power Supply.

Dell Support, and the Service Manual main page, for the Dimension E310,

http://support.dell.com/support/edocs/systems/dim3100/en/sm/index.htm

If you click on Technical Overview, then on System Board Components, you'll be taken to this page,

http://support.dell.com/support/edocs/systems/dim3100/en/sm/techov0.htm#wp1058089

Here you will see an illustration of your motherboard. This is a Top view. The view you will see when you open your computer case.
(Main menu - Removing the Computer Cover)

The number 9 points to the ATX main power connector on the motherboard.
Viewing closely you will count 24 socket holes.
12 on top, 12 on bottom.

This connector is a 24-pin ATX main power cable connector.

If you scroll down the page to the heading - Power Supply DC Connector Pin Assignments, and to the heading underneath - DC Power Connector P1, you will see the Dimension E310 has a 24-pin ATX main power cable.

This is a more in-depth view of a typical 24-pin ATX main power cable, and it's respective connector, plus a view of a typical 24-pin ATX main power cable connector, on a motherboard,
(Not a Dell Dimension E310),

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

The photo to the far Left, shows a 24-pin ATX main power cable connector, on a typical motherboard.
There is no 24-pin ATX main power cable plugged in.

The photo in the middle, shows a 24-pin ATX main power cable.

The photo to the far Right shows the 24-pin ATX main power cable plugged into the connector.

In the photo to the far Right you will see that one of the power wires has Green insulation.
This is the Soft Power On wire.
Also abbreviated as PS_ON

You will see many wires with Black insulation.
ALL of these wires are a Ground wire.

The jumper wire is connected to the Soft Power On wire, (Green), and to ANY Ground wire. (Black)

The method is to insert one end of a jumper wire, into the socket hole with the Green wire, and the other end into a socket hole with a Ground wire.
(ANY Ground wire)

Again looking at the photo to the far Right, you will see that the power wires go down into individual socket holes.
The insulation of the power wires goes down into the socket hole pretty far.

At the end of each power wire is a metal terminal. It is a female terminal.
This is what it looks like,

http://www.alliedelec.com/search/productdetail.aspx?SKU=8630463

The jumper wire must go down into the socket hole, (Right next to the existing wire already in the socket hole), far enough to touch that metal terminal pin.

it has been suggested to use a paper clip.
The paper clip is straightened out, then bent into a U shape.
The center of the U shape is wrapped with black electrical tape.

The taped area is where you hold the 'jumper wire'
You may wish to wear a glove also.

The voltage is 5 Volts DC.
Two D cell flashlight batteries produce 3 Volts DC.

There may be a spark.
Hence I advised wearing a glove. Not so much for your safety, but for your peace of mind.

One end down into the socket hole with the Green wire, (Soft Power On), and the other end down into ANY socket hole with a Black (Ground) wire.

The contact period used is no longer than 2 seconds.

If the Power Supply comes on, you have a bad Power On switch.
If the Power Supply does Not come on, you have a bad Power Supply.

The Power Supply can come on, and still be bad. Weak voltage power rail.
Enough power to light LED lights, and perhaps spin fans, but not enough to turn the Processor on.

1) ALL of the LED lights combined, use less than 1 Watt of power.
2) EACH fan uses 2 to 3 Watts
3) A typical Processor can use 51 to 125 Watts.

Post additional questions in a Comment.
Regards,
joecoolvette