20 Most Recent Gateway Bestec ATX-300-12EB3 305w Power Supply (ATX30012EB3) Power Supply Questions & Answers

angeldram3
as i think ur processor over heated. or processor can dos not work fine or heat sink not installed properly. remove heat sink, and use heat sink component (a whithe colour gel. u can buy it any computer accessories shop) use it top of ur processor then attached heat sink. and connect processor fan. before installing heat sink check processor fan. then cleare CMOS by removeing battery (because this problem also can happen wrong frequency setting in CMOS setting).

change the fuse inide the power supply.it may be broken

Yes.

The Power Supply has a weak voltage power rail.

1) If ALL of the LED lights were on at once they would use less than 1 Watt of power.
(Amperes, {Amp's} times Voltage = Watts)

2) EACH fan uses 2 to 3 Watts of power.

3) A typical Processor may use 51 to 125 Watts of power. Just depends on what Processor it is.


A) Yellow light is a Diagnostic light. Blinking yellow tells you the Power Supply is bad.

B) When you unplug the 24-pin ATX main power cable from the motherboard, you have relieved the Power Supply of a load, temporarily.

The power supply then builds up enough power, that when you plug the 24-pin ATX main power cable back in, the fans run long enough until the built up power is drained.

How?
Inside the Power Supply are Electrolytic Capacitors.
They are used as Filters.
They filter the incoming AC electricity, and the outgoing DC electricity.

(They are in the Input Stage, and the Output Stage,

1) http://en.wikipedia.org/wiki/File:PSU-Open1.jpg

2) http://en.wikipedia.org/wiki/Switched-mode_power_supply

Click on the photo at the top right, to enlarge.

The first link above shows a side view.
The second link shows a top view.

The round objects that have a B on them are Electrolytic Capacitors.
They are in the Input Stage.

The ones to the right that surround the letter E, are also Electrolytic Capacitors, and they are in the Output Stage.

Basic construction of an Electrolytic Capacitor used in your power supply, is an aluminum shell case, three strips with a lead off of each one, (Wire), a cap at the top, a cap at the bottom, and Electrolytic Paste.

A) Three Strips:
1) One strip is a metal foil strip with the Positive lead attached to it.
It is the Conducting Strip.

2) One strip is a metal foil strip, and has a Non-Conducting medium applied to it.
It has the Negative lead attached to it.
It is the Non-Conducting Strip.

3) The last strip is a paper composite, and is soaked with Electrolytic Paste.

The case is a cylindrical aluminum shell.
At the top there is a flat, round aluminum disk. It has a K or X shape etched partway into it.

At the bottom is a round, flat synthetic rubber disk. It is the Bung.

The paper-like strip is laid in-between the two metal strips, and all three are rolled up tightly.
The two leads from the Conducting strip, ( + ), and the Non-Conducting strip ( - ) are inserted through the rubber bung at the bottom of the capacitor.

As an Electrolytic Capacitor fails it builds up gas inside. (Hydrogen Gas)
{Gas is created from the Electrolytic Paste }

The gas expands, and begins to push Electrolytic Paste out.
So much paste loss, and the capacitor operates, but at a weakened state.
Too much paste loss, and the capacitor fails.

This is why the computer may have turned on one time, and not the next. Then it fails to turn on at all because of a bad power supply.

This is NOT an invite to open your Power Supply, and attempt to repair it.
Those large capacitors shown in B, (Input Stage) may still be good.
Usual voltage ceiling for them is around 100 VOLTS!

If your fingers touch the two terminals on the bottom of a capacitor, (Radial Aluminum Electrolytic Capacitor), the stored power can be released to YOU!

If your fingers, or any of the rest of your hand, complete a circuit that any of the capacitors are in, the stored power can be released to YOU!

Shock can be from BAD to FATAL.

See if there is an unused computer with a good, compatible power supply, that you can borrow for a test unit.
Also make sure your computer is clean inside.
Dust, dirt, hair, food crumbs, spider webs, etc., will 'Kill' a Power Supply, and a computer F-A-S-T!

{It's just an ATX power supply. The type used in a LOT of desktop personal computers.
If you need a recommendation for a PSU, just hit me up in a Comment}

For additional questions please post in a Comment.

Regards,
joecoolvette

I'll assume that your old PSU is also an ATX. First, the plug that has a few dozen wires arranged in a rectangle goes into the MB. Your PSU's ATX connector may be split into 2 parts: the AT portion and a square portion with 4 wires. Together, they make an ATX plug. You'll find some tiny plugs with 2-3 wires for your onboard fans. You might find a few slightly larger flat plugs with 4 wires for old floppy drives. The rest should be the regular MOLEX plugs and slim SATA power plugs for your drives.

you might have a faulty PSU power supply unit if the units fan is intermittent and your computer restarts at any time you could try plowing all the dust from it using a high pressure air blower from a compressor make absolutely sure there is no moisture in the airlines you will have to open up your computer to blow the dust from your psu and blow the dust from inside to outside through the back of psu while you are inside your computer blow all dust from your computer
if you have any problems with this post a reply
hope this helps

unplug the power supply from the wall socket. check if there is any debris on the fan.. if there is just clean it. but if you have a extra fan just replace the old one... and it is not advisable to repair that on the local repair shop because it will cost you as a brand new one... ty

Your reasoning about the switch mode power supply being damaged is probably right.
Bear in mind that this power supply may not be the only thing that may be damaged in your computer.
You won't know for sure until you borrow a power supply and install it into your computer to see if it will work again.

Test your PSU or replace it if your power supply units fan is not working your PSU is faulty

One bad lead can cause a computer to continue on a cycle or to shutdown or fail to detect/ boot up a computer hard drive

Test all leads that attach to your hard drive including electrical extensions,IDE,SATA

the leads from your "((MOTHERBOARD TO YOUR HARD DRIVE))" make sure they have a secure connection and are not faulty or just replace them they could be faulty make sure all leads that are attached to your drives dvd\cd 3 1/2 inch floppy have secure connections and are not faulty even the electrical extensions or just replace them they could be faulty a computer needs its connections to continue its cycle and have an end so any faulty leads will end up with a computer error even something as small as a faulty electrical extension or fan lead can cause this problem hope this helps

Test your PSU or replace it if your power supply units fan is not working your PSU is faulty
hope this helps also

One bad lead can cause a computer to continue on a cycle or to shutdown or fail to detect/ boot up a computer hard drive

Test all leads that attach to your hard drive including electrical extensions,IDE,SATA

the leads from your ((motherboard to your hard drive)) make sure they have a secure connection and are not faulty or just replace them there probably old and faulty make sure all leads that are attached to your drives dvd\cd 3 1/2 inch floppy have secure connections and are not faulty even the electrical extensions or just replace them they are probably old and faulty a computer needs its connections to continue its cycle and have an end so any faulty leads will end up with a computer error

hope this helps

get it replaced with a new one, atleast 450w

The quickest and easiest method.
Beg or borrow another power and connect it to your computer.

the PSU has Problem . It is not supplying enough voltage to boot the PC, capacitors inside the PSU are weak or damaged. Its dangerus to open the PSU coz, Capacitors have high voltage currents. If you have the Knowledge of electronics, then open the PSU and detect the Weak or Leeky Capacitors and replace them with new one( this method is for experiment and thrill) . But the replacement new PSU is better , perfect and cheaper then repairing the psu from outside. best of luck

Test your PSU or replace it if your power supply units fan is not working your PSU is faulty

My gateway was powered up and I came back into the room and it was not. It would not turn on so I checked the power supply with the paper clip jump method (which is the only thing I know how to do) and the green light along with the fan turns on. While it is plugged into the pc, it blinks with no fan running. The power supply is an ATX 300-12EB3. The Gateway is 556GE. Thank you for any help I can get on this.

The power supply should be a standard unit. There is the odd one that has special connectors or mount holes but those aren't as common as they used to be. You should be able to get any 300 watt or larger ATX power supply and drop it in. All you need to do is make sure you get the same watt rating or larger. So you could go with a 350, 500 etc. The larger the power supply rating the more connectors it will have.As long as you have the right connectors for the motherboard cpu and then enough for all of your drives and video card or other devices then you are good to go.

The best thing you can do is take the old one out and take it with you. That way you or someone at the store can check that you have the right new power supply.

First off what is the make and model of the computer/motherboard. How long have you owned it and how long have you had this problem? Have you tried switching power supplies? At this point it could be power supply or motherboard. Once I have more info I will assist you further.
Thank you,
Lee

It is a very an old question. I had this problem myself at an early age.
Here is an image that will help you:
These are small, 2-pin cables that are in Red, Blue and Green colors (with white main connector). Try to not bend te pins receptors, because they are very fragile.

1. Plug the POWER_SW cable on the first two left pins;
2. Plug the HDD_LED cable next to it;
3. Plug the POWER_LED cable either to the insulated 2-pin slot or next to the two others you plugged in;

Be carefull because if you missplace the order your system won't power up, and insert them horizontally.

If you need further assistance, please post.

If it has fan power than all is well. The newer models can handle a zip verywell. What cannot handle it is RAM.
Most new power supplies have their own switch and it often times has a power off..