Why does green light flash on atx-300-12z-300. computer will not even get power now, not even too the fan

u can buy power supply testers, just a device you plug the power supply into, or try a new power supply. but if nothing is happening no fans etc theres a good chance its just the power supply.

If you didn't accidentally unplug the four pin connector near the CPU, you need to replace the power supply. This is actually a fairly common occurrence with the cheap ATX power supplies being tossed into systems these days.

Yes - replace the power supply. It is flashing because the regulator is bad or there are bad capacitors in the power supply.

The Green LED light you see flashing indicates you have a bad Power Supply.

Computer unplugged from power, computer on a table, computer case open, observe Anti-Static Precautions.
Clean the inside of the computer out with a can of compressed air for computers, (Or may take two, and a few Q-tips), and replace the Power Supply.

Supporting data:

HP Support > Pavilion 523w desktop computer > Main support page,

http://h10025.www1.hp.com/ewfrf/wc/product?product=90859&lc=en&cc=us&dlc=en&submit.y=9&submit.x=7&lang=en&cc=us

Click on > Solve a problem > Start Up/Shutdown/ Power > Power Management

Click on the + sign to the left of > Power supply light is on or flashes


Replacing a Power Supply,

1) http://www.fonerbooks.com/r_power.htm

2) http://www.videojug.com/film/how-to-install-or-change-my-computers-power-supply

The Power Supply is an ATX form factor. The ATX style of Power Supply is found in over 80 percent of personal computers out there, and is readily available everywhere.

It's a 250 to 300 Watt power supply.
Probably made by Bestec, HiPro, or Delta, or some other generic power supply manufacturer of low quality power supply's.

Has a 20-pin ATX main power cable, and a 4-pin ATX +12 volt power cable.
Plus the usual amount of 4-pin Peripheral power cables, and a Floppy Disk power cable.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=bph07845&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&product=90859&lang=en

Scroll down to the illustration and photo of the Motherboard.

Typical 20-pin ATX main power cable,

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

Typical 4-pin +12 Volt power cable,

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

use a different working power supply to test it

if the cooling fan on your PSU power supply unit does'nt spin when you start your PSU is faulty if it does then
replace all the leads that attach to your hard drive including electrical extensions + IDE,SATA the ones that attach from your motherboard to hard drive
make sure all leads that are attached to your drives dvd\cd 3 1/2 inch floppy have secure connections and are not faulty or just replace them they are probably old and faulty ?
hope this helps

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

The green light flashing is a diagnostic LED light, telling you there is a power failure.
More specifically a bad Power Supply.
Weak voltage power rail.

The Power Supply used in a Compaq Presario SR1010Z desktop computer, is a 300 Watt unit, and is an ATX form factor.

[ATX form factor for a Power Supply, denotes the size of the Power Supply case, and the shape.
It is approximately 6 inches Long, 6 inches Wide, and 3-1/2 inches Tall.
The ATX form factor for a Power Supply is used in over 90 percent of the personal computers out there, and is as readily available as the air we breathe]

Usually, HP uses one of three generic Power Supply manufacturers.
1) Bestec
2) Delta
3) HiPro

All are low quality Power Supply manufacturers.

This is HP Support, and the main menu page for the Compaq Presario SR1010Z desktop computer,

http://h10025.www1.hp.com/ewfrf/wc/product?product=1146324&lc=en&cc=us&dlc=en&submit.y=7&submit.x=6&lang=en&cc=us

If you click on Manuals, then on Upgrading and Servicing Guide on the following page, there are instructions on how to open your computer case.

This is instructions on how to replace a Power Supply, from HP Support,

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01356113&cc=us&lc=en&dlc=en&product=3548196

(It's for a Pavilion a6230n desktop computer, but after you open the computer case of your Compaq Presario SR1010Z, the instructions are the same)

What Power Supply would I recommend?
There are 100's to chose from.
This is but one example,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3276575&CatId=1078

Chosen because;

1) Maximum wattage is rated at 450 Watts.

A computer ONLY uses the power it needs, and NO more.
Wouldn't matter if you had a 10,000 Watt power supply, (No such thing. An exaggeration), if your computer only needs 100 Watts, it would only use 100 Watts.
(Surfing the internet typically uses 100 watts)

2) Has all the power cables you'll need, and more. Tie up the power cables you do not need. (Use plastic ties, Not wire, or bread wrapper ties)

3) 24 Amperes (24A) on the 12 volt power rail.

4) 135mm cooling fan.
The cooling fan on the Power Supply you have now is 80mm.

A larger fan turns slower. Produces as much air as a smaller fan, (Or more), but makes less noise.
Less wear on the fan's bearings also.

5) Is an ATX form factor Power Supply.

6) It's 80 percent efficient, compared to the 60 percent efficient Power Supply you have now.
(That is, if it was working)

Hi. NO, *********** board is not fried. I am not sure what the problem is but I do know how to fix it. It is usually casued by power outages (even if you have UPS supply).

1. TAKE OUT THE ELECTRICITY LEAD TO THE COMPUTER. Look inside the computer and find the bunch of wires coming from the power supply unit (the box thing at the top with the fan and all those colouted wires!).

2. Find where these wires run into a plastic connector and plug into the mother board. Unplug it.

3. Now plug the electicity lead back into the computer. The light should now stay ON.

4. Plug in the connector again... and boot up. Leave it run a while to convince it!

5. Repeat this process if it does not work first time.

This should fix your problem . It works for me when I get this problem.

Friend in Spain

I had the same issue and accidentally discovered a temporary solution. Unplug the power from the back of the machine, open the case and unplug the ATX power connection from the motherboard. With the ATX cable unplugged, plug the power cord back in. When you try to turn the computer back on the power light should turn orange and fans should be spinning, with it powered on plug the ATX connector back in. That should turn the computer off. Turn it back on and it should boot fine. You can even shutdown and restart, but when the power is unplugged you will have to go thru the same process to get it back up. This sounds crazy but it worked on mine. Good Luck!