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How to replace a computer's power supply

The power supply is one of the most common components to fail inside a desktop computer. If you don't mind turning a screwdriver, you can replace a bad power supply yourself and save on repair costs.

Before purchasing a replacement power supply:

- Make sure to get a power supply that is rated for at least the same wattage as your current power supply.
- Verify that the new power supply has all of the necessary connectors that your current one has. You can either check this visually by looking at the connectors that you have, or by making sure your computer is listed as one of the models that the new power supply is compatible with.
- Make sure the new power supply will fit inside your computer's case. (If the new power supply is compatible with your computer, that won't be a concern.)

To install the new power supply:

- Turn your computer off and unplug it from its power source.
- Unplug all of the cables leading from your computer, including the power cable.
- Open the computer's case. (If you're not sure how to do this, you can probably look it up online. Most computers either have screws in the back that come out, a side panel that slides off, or they open up like a clamshell.)
- Disconnect all of the cables leading from your power supply. Note what component each connector plugs into. You should have connectors for your fan(s), hard drive(s), optical and/or floppy drive(s), motherboard (may be one or two connectors), and the front power switch.
- Unscrew the power supply from the system case and remove it.
- Set the new power supply in the case facing the same way as the old power supply and screw it in.
- Attach all of the connectors. (You may have more connectors than components, but make sure each component that was connected before is connected again now.)
- Close the system case and reattach any screws.
- Plug the power cable into the power supply and then into the wall outlet.
- Reattach all other cables.
- Make sure the power switch on the back of the power supply is on.
- Make sure the voltage switch on the back of the power supply is set to the correct voltage (115 volts in the United States).
- Turn on the computer and verify that it boots up correctly.

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power supply not coming to mother board. how can i find weather its will work or not? how can i troubleshoot ? hoping the detailed information regarding this.....


If your computer does absolutely nothing when you power it up - the fans don't turn on, no lights turn on and the the monitor screen stays dark, some component inside your personal computer has failed. Unfortunately, there are no visible fuses that you can replace. There's a good chance the power supply has failed however you need a PC power supply tester to test it. However, there are other components in your computer which could have failed and cause the computer to do nothing when you power it up. If you have the required tools, test equipment and understand how these components work you can test them and determined which component has failed. Otherwise, you need to have a computer technician determine what your problem is.
I'm sorry that I can't help you more, but repairing computers is similar to repairing automobiles . If my car will "turn over" when I turn the key on but will not start, I could replace the fuel filter, fuel pump, coil, ignition computer etc. until I found the problem, but I don't have the parts/tools, I don't know how to test automotive problems and I don't want to waste money and possibly cause more damage by just guessing. I take the car to my mechanic for repair.
If you have any additional questions contact me by clicking on the "Add a comment" link located under your problem description on FixYa. Also, if you believe that this information was helpful to you, please rate my solution using FixYa's "Solution Helpful" rating scale.
Best regards,
Yavacotech

Jun 28, 2011 | Mercury Computers & Internet

1 Answer

power botton wont turn on


If your computer does not power up at all, or if your computer powers up (the fans turn on) but the monitor screen stays dark and /or the operating system does not load, Some component inside or attached to your personal computer has failed. These include the monitor, power supply, CPU, motherboard, hard drive, display adaptor, memory etc. If you have the required tools and test equipment , and you understand how these components work you can test them and determined which component has failed. Otherwise, you need to have a computer technician determine what your problem is.
I'm sorry that I can't help you more, but repairing computers is similar to repairing automobiles . If my car will "turn over" when I turn the key on but will not start, I could replace the fuel filter, fuel pump, coil, ignition computer etc. until I found the problem. However, I don't have the parts or tools or the test equipment to test the parts with, and I don't want to a guess at what part has failed and spend money buying replacement parts which may or may not solve the problem. I take the car to my mechanic for repair.
If you have any additional questions contact me by clicking on the "Add a comment" link located under your problem description on FixYa. Also, if you believe that this information was helpful to you, please rate my solution using FixYa's "Solution Helpful" rating scale.
Best regards,
Yavacotech

Jun 26, 2011 | E-Machines eMachines Desktop PC

1 Answer

I have an Acer Aspire AM1641 U1521A desktop that will not boot up. No beeps, errors or monitor activity. Do I need a new hard drive, motherboard...?


Power Supply. Weak voltage power rail.

Has enough power to light LED lights, maybe spin fans, (Or spin a few times, and stop), but not enough power 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 of power.

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

Acer Aspire M1641-U1521A?
Intel Pentium Dual Core E2180 (2.0GHz)

http://en.wikipedia.org/wiki/List_of_Intel_Pentium_Dual-Core_microprocessors#.22Allendale.22.2C_.22Conroe.22_.2865_nm.29

Can use up to 65 Watts. (TDP)

The Power Supply used is a 250 Watt unit. Acer isn't known to use high quality power supply's. It's a generic low quality Power Supply.

[ However in all fairness to Acer, if the inside of the computer, AND the inside of the Power Supply, isn't cleaned out on a regular basis as needed, this can cause Power Supply failure also.

Use a can of compressed air for computers, with the plastic 'straw' attached. Hold onto the can with one hand, use the other hand to hold onto the straw, shoot air through the ventilation holes of the Power Supply's case. (Computer unplugged from power)

Come around to the back of the computer, use the air to clean the Power Supply's fan blades, center hub, and surrounding cage. (Shroud)

When the cooling components for the Power Supply, (Fan and Heatsinks used inside), become clogged with dust, dirt, etc., the cooling capacity drops tremendously.

The Power Supply overheats.
Heat = Wasted Energy

The Power Supply strains to keep up with the call for power, but eventually cannot, and fails.
Components inside the Power Supply fail ]

Replace the Power Supply.

Sep 28, 2010 | Acer Aspire M1641-U1521A PC Desktop

1 Answer

when powered on - the fans spin, but no display on monitor, no beeps....... for hp a1410n


Suggest you have a bad power supply. Weak voltage power rail. Enough power to light lights, and spin fans, but not enough to turn the Processor on.

1) ALL of the light require less than 1 Watt of power.

2) EACH fan uses 2 to 3 Watts

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

If this is an HP Pavilion Media Center a1410n Desktop PC, it comes with an AMD Athlon 64 3800+ processor. (2.4GHz)

(The 64 stands for 64bit. It is a 64bit processor. The 3800+ is AMD's model number. The maximum frequency rate is 2.4GigaHertz)

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00607954&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&lang=en&product=1841799

The AMD Athlon 64 3800+ processor when operating at maximum capability, can use 89 Watts.

http://en.wikipedia.org/wiki/List_of_AMD_Athlon_64_microprocessors

What made the Power Supply fail?
1) Computer is dirty inside, as well as the power supply.
The cooling components for a power supply are Heatsink's inside, and the external fan.

When the cooling components get clogged up with gunk, the cooling capacity drops tremendously.
Heat = Wasted Energy

The power supply tries to keep up with the call for power, and eventually components inside the power supply fail.

2) Pre-built computer manufacturer's tend to put low quality power supply's in their computers. Saves them money.

Do you wish to know how to test your power supply? Do you have a multimeter, or a power supply tester?

One example of a power supply tester,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5250576&CatId=1107

Also, do you wish to know how to replace your power supply?

Apr 10, 2010 | HP Pavilion a1410n (ER890AA) PC Desktop

2 Answers

My a730n will not turn on and the green led power light on the back is flashing


This indicates there is a problem with the Power Supply.
You have a weak voltage power rail.
Components inside the power supply have failed.

Most of the time this due to the power supply, as well as the inside of the computer is dirty.
The rest of the time it is due to a cheap quality power supply from the computer manufacturer.

You can be the best housekeeper in the world, but inevitably dust, dirt, and other material is drawn into your computer.
Your computer uses air to cool the hardware components inside.

Air is drawn in through the front of the Pavilion a730n, and is exhausted out of the back.
(There is one computer case fan in the back, and the Power Supply fan also helps)
This is the computer's Cooling System.

The cooling system for the Power Supply is a fan on the back of the unit, and Heatsinks that are inside.

(A Heatsink is a small plate of metal, with tall fins on it. The Heatsink works as a small radiator. Heat is absorbed up through the fins. Air is drawn through the fins, and heat is pushed away by the air)

When the fan blades, center hub, and surrounding cage become clogged with the above mentioned material, the cooling capacity drops tremendously.
Same thing for the Heatsink fins when they become clogged.

Heat = Wasted Energy
The Power Supply strains to keep up with the power load that is needed, and the additional loss of energy, (Power), that is lost due to heat.

Eventually components inside the Power Supply fail.

Commonly it is the Electrolytic Capacitors that fail first.

Computer manufacturer's commonly use cheap quality Power Supply's. They buy them from a Power Supply manufacturer.
Cheap quality = the computer manufacturer saving money, because the unit's cost them less.

1) Cheap Electrolytic Capacitors
2) Too small of a gauge of wiring is used
3) Cheap quality Rectifier Bridge
4) Cheap MOSFET's
The list goes on.

Solution is to replace the Power Supply.
Power Supply's come in many sizes, and power designations.

The HP Pavilion a730n uses the common size, and shape of Power Supply, used in 90 percent of personal computers. ATX

The power designation is 300 Watt.
Usually it is a Bestec, Delta, or HiPro power supply that is used.
C-H-E-A-P!

Based on personal experience, I would recommend this power supply for a replacement unit,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4675269&CatId=1078

Not an advertisement for said website. You may find a better price by searching.

Know this:
A computer only uses the power it needs, and no more.
Example:
You could install a 1000 Watt power supply in your computer, (Not actually. It will not fit), and if your computer only needs 100 Watts,
it only uses 100 Watts.

(Typically surfing the internet uses 100 Watts. Same as a 100 Watt light bulb)

This is HP Support, Pavilion a730n, and the Manuals page,

http://h10025.www1.hp.com/ewfrf/wc/manualCategory?lc=en&dlc=en&cc=us&product=431078&lang=en&

On this page you can download the Part Replacement Instructions manual.
Has large illustrations, to show how to replace parts inside the Pavilion a730n Desktop PC.

Power Supply replacement is shown.

From me:
If this is your first time in replacing a computer hardware component, this may seem like a daunting task. Once you are finished you'll realize it wasn't all that tough.

Inside your computer you'll see many cables, (Wires)
You'll see cables coming from the Power Supply, that go to the various hardware components inside.
(Motherboard, Harddrive, and CD/DVD drive/s)

Power cables from Power Supply
1) You have a cable with many wires in it. It has a white connector on the end, and is long in shape.
It has 24 socket holes.
It's a 24-pin ATX main power cable.

Connects to the motherboard. To release it from the motherboard, there is a lock tab on the side of the connector. Press the lock tab at the top. This pivots the lock tab, and draws a hooked end, out of the side of the motherboard connector.

Gently wiggle the connector side to side, while depressing the lock tab, ease it up.
(Side to side lengthwise)


2) You have 4-pin Peripheral power cables. (Also referred to as Molex)
White in color, 4 wires. (Red, Yellow, and two Black)

One to each CD/DVD drive you have.

3) You have One SATA power cable. Connects to the SATA Harddrive

4) You have One 4-pin ATX +12 power cable. The connector is square in shape.
Has two Yellow wires, and two Black wires.

This power cable is for power to your Intel Pentium 4 processor, and Must be plugged in.
Plugs into the motherboard.

This link shows the various power cables, and connectors, that I listed above.
(Large photos, and clear information)

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

(Scroll the page down, to view all of the power cable connectors. Click on a photo of a connector, to view more information about it)

Should you need more information, just click on Comment, and type it out. (Believe top right of your page)

Jan 12, 2010 | HP Pavilion A730N (PJ510AA) PC Desktop

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