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Power supply problem? 24 pin connector

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October 31, 2008 4:23:41 AM

Ok first off i'd like to say i'm not too tech savy so bear with me.

I'm trying to piece a system together with the following components
Athlon64 X2 3800+ on socket 939 (Toledo core)
OCZ Vindicator CPU cooler
Asus A8N-SLI SE socket 939 motherboard with nForce4SLI chipset
ATI x1900 512 crossfire edition card (using a single card stand alone)
1gb of ram
2x hard drives
(all known to be working other 100% not sure about power supply)

Power supply is IN WIN IP-P460Q3-2 460W ATX12V V2.2
same one as below but none retail model, same specs and connectors etc however.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

So heres my problem, Mobo has 24 pin connector... Power supply has 20pin +4 pin connector I plug everything in, theres a green light lit on the motherboard... hit the power button and all it does is move the fans for a second then nothing. Everything is hooked up at this point so I try to disconnect the hard drives but keep the PCI-E plugged in and give it another go, same results. I don't remember but I think I tried with the PCI-E unplugged with the same results.

So I thought it was maybe the Inwin power supply is bad so I try out a very old power supply I had sitting around... 300-350W Cool master (if I remember correctly) It also had a 20pin +4 pin connector no PCI-E connector however. I plug it into the mobo, and voila everything fires up.

I retest the Inwin power supply on an older AMD 3000+ system with a 20 pin and the older system fires up no problem with the Inwin. It seems like the Inwin works for the 20 pin... however when used with the +4 pin for my 24pin Asus mobo it doesn't seem to work?

Am I missing something? noob overlooking something?

Does the Inwin have a problem with the 4 pin connector? do I need to replace this Inwin psu?

Also upon examination the Inwin's 20 pin connector is missing a pin like inwin pictures below theres no wire going into that pin
http://c1.neweggimages.com/NeweggImage/productimage/17-...
The coolmaster (that worked) didn't have this missing pin and had a white wire going into this pin

Not sure what it means but i'm trying to get as many details as possible

Thanks ahead of time
October 31, 2008 5:10:20 AM

agente: your powers of observation are to be commended and yes you are correct you will need a 20+4 pin connector,if the mobo requires it,one thing though,do not rely on an elcheepo power supply,it is the heart of your system,if you are thinking,at the back of your mind of a future up grade,then take that into consideration and go forth and secure thyself a good power supply,like enermax,ocz,cooler master,,, whatever ..:) 
October 31, 2008 5:26:56 AM

I would get a better psu. Corsair is my fav but even a thermaltake or coolermaster is better than what you have...
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October 31, 2008 11:58:49 AM

If it start's fans spinning for a second then stops, you may be short-circuiting it. (happened to me with my first sysytem).

Make sure you don't have anything unnecessary connected, and that nothing is touching the mobo that shouldn't. (e.g loose screw may be trapped beneathe mobo)

If you can't see a problem try starting with just processor, video card, and memory, (and only external devices as keyboard mouse and monitor) and see if it works, if it does, then one by one reconnect everything else untill (if) you find the problem.
October 31, 2008 12:25:04 PM

Lots of PSU's have a 20 +4 style connector for maximum compatability. That way you can have a 20 pin MoBo and not have to worry that your PSU isn't going to hook up with it. A lot of people who don't build that often make the mistake of not hooking up the 4 pin CPU connector because they think the +4 pin takes care of that. Make sure you have all of your connections in.
a c 121 ) Power supply
October 31, 2008 2:05:22 PM

I think most people around here would highly recommend In Win to hold down your garbage can in moderate wind; several may be needed to be sure you have enough weight.
Antec, Corsair, PC Power & Cooling, OCZ, Enermax, Seasonic or FSP would be among the brands more suitable to power computer systems.
-------
On another note, that older mobo may want a -5V rail which is often missing from modern PSUs. If so, your choices will be very limited. Here are three though:
1. http://www.newegg.com/Product/Product.aspx?Item=N82E168...
This CoolerMaster is $45. It is labeled 500W, but is probably actually not a half-bad 400W PSU; enough for that rig. Uses a cheap sleeved fan though, which may not last.
2. I might get lambasted for this one, because the Apevia (Aspire) brand is a four-letter word in some languages, but http://www.newegg.com/Product/Product.aspx?Item=N82E168... has the rail you need also. A couple of precursors to this were the last cheap PSUs I ever bought. I used them in s939 rigs, where they were probably not expected to provide much over 250W. One ran for over a year until I rebuilt it, and the other one ran for over two years before the rig died. I have not had a chance to determine the cause, but have no particular reason to suspect the PSU.
3. This Mushkin has the rail you need too: http://www.newegg.com/Product/Product.aspx?Item=N82E168.... It is also modular; actually a fairly nice PSU. Is it worth spending $85 on a PSU for this rig? This is not a remarkably efficient PSU, and doesn't have Active PFC, so you might not want to re-use it either. Consider it only if you're going to use the current build for an extended period of time and can justify the price.
October 31, 2008 5:55:03 PM

Some old motherboards or ISA expansion cards require -5v.
-5 volt support has been optional in PSUs since ATX12V 1.3 because it's rarely used anymore. It's rarely included in new PSUs. But some old motherboards or ISA expansion cards require -5.
October 31, 2008 6:00:44 PM

Older PSUs deliver most of their wattage on 3.3 and 5 volts and newer ones deliver most of it on 12 volts. You can definitely have problems using an old 300 watt PSU in a new computer which needs a 300 watt PSU even if the power connectors are compatible. It's very easy for a new computer to overload the 12 volt rail of an old PSU. You can also have overloading problems sticking a new PSU into an older computer. Most ATX12V 1.3 and earlier PSUs provide enough 3.3 or 5 volt power to run an older motherboard but some newer ATX12V 2.0 and newer supplies have reduced the available power on 3.3 and 5. If you're using a new supply with an older motherboard then it's best to check that it has enough wattage on 3.3 and 5.
October 31, 2008 6:02:06 PM

I have a feeling the OP has not been paying any attention to this thread.
April 27, 2009 11:53:49 PM

evongugg said:
Older PSUs deliver most of their wattage on 3.3 and 5 volts and newer ones deliver most of it on 12 volts. You can definitely have problems using an old 300 watt PSU in a new computer which needs a 300 watt PSU even if the power connectors are compatible. It's very easy for a new computer to overload the 12 volt rail of an old PSU. You can also have overloading problems sticking a new PSU into an older computer. Most ATX12V 1.3 and earlier PSUs provide enough 3.3 or 5 volt power to run an older motherboard but some newer ATX12V 2.0 and newer supplies have reduced the available power on 3.3 and 5. If you're using a new supply with an older motherboard then it's best to check that it has enough wattage on 3.3 and 5.



Thank you so much for that information. I am having a similar problem and your explanation finally gave me an answer to my frustrations.

My parent's have an older computer and their power supply just died. I went online and bought the cheapest one I could find because I knew that they were not using it for more than simple web browsing. They used to have a 250 Watt generic power supply in there and I tried replacing it with a Dynex 400W PSU. The new one I bought was only 15 bucks on ebay cause it was an open box item. I tried plugging it in to a new motherboard first and it ran fine. Then i tried it with the older one and it would not start at all.

At first I thought the front panel I/O headers were wrong and I kept re-arranging them til i went crazy. Then I thought it was a problem with the 20 pin ATX connector since i was using a 24 pin to 20 pin adapter. I thought that it was not good or something but I did not bother buying a new one.

Now I just have to go back to ebay and try to find an older 250 Watt power supply...yay :??: 
April 28, 2009 12:01:29 AM

Unplug the power supply from everything except the motherboard and see if it powers up then. If so, start pluging one thing in at a time and check for powerup. This may be able to help you pinpoint the problem.
May 4, 2009 1:27:10 AM

It turns out that the front I\O panel configuration on the motherboard was my problem. I did not know what motherboard i was using at first, not even the manufacturer. Eventually I tracked down the model number and everything and found a manual to the board. I found the correct placement for the front I\O panel. I realized I was using the USB headers and the right ones were in this jumble of like 12 pins.

Nothing was wrong with either the mobo or power supply, It posted no problem. Now i just have to figure out how to get windows to work again without reinstalling the os. yay ... :??: 

I could just backup the hard drives and re-install the OS, but this is a bit low on my to-do list because it is not my main computer.
May 4, 2009 1:32:00 AM

Oh and i also want to make a note that i swapped out a generic power supply from a newer computer for the 400w that I just bought. I found that the generic one was just what i needed for the older computer because it had the -5 volt support and had 3v ratings higher than the 400w one i got on ebay. The generic one still had sata and pci-e connectors and it was 280watts.
I put the newer power supply in the newer computer. It was a win-win situation.
!