Problem with Power Supply Compatibility

StillLearning

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Can anyone help me with a PC Power Supply Compatibility problem.

I have an ASUS P4C800-E Deluxe motherboard. The Turbo-Cool 510 SLI Power Supply that I was using failed.

I ordered a Corsair CMPSU-750AX power supply. After I unpacked the unit, I had a couple a minor questions about the cables and sent an email to the Corsair tech support.

They replied almost instantly with the answers and added that the new Corsair power supply would not work with the ASUS motherboard. The power supply was ATX v2.3 Spec. and was not backward compatible with the ATX v1.3 Spec. motherboard.

The only new ATX v1.3 power supply I can find is a Rosewill 350 watt unit. I already know that 350 watts will not run my PC.

Is anyone aware of any ATX versions that came out after v1.3 that are backward compatible with the v1.3?

Maybe it will increase the chances of finding something that will work if there were a greater number of ATX versions to select from.

Thank you.
 

lilotimz

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AX750 has a 20+4 pin ... i'm pretty sure and it should work i think....

Plus why would you replace one of the best PSU today for a crap like a cooler master GX? "
(corsair AX is based off Seasonic X series, one of the best rated in existence)
 

lilotimz

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Corsair AX750 750W
Type of connector: Quantity
Modular Cables
ATX 20+4 pin connector (600mm)

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=236

I'm just saying that it has a 20+4 pin ... which is what most reviews also say....
 

StillLearning

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Yes, the Corsair power supply has a 20+4 pin connector.

But, here is the problem I am trying to work around:

From RAM GUY at Corsair - - -

“I am sorry but that PSU will not work with that MB, it requires ATX 1.3 Spec PSU. Our PSU is made to the ATX 2.3 Spec.”

After that statement, I didn’t want to plug in the 20 pin portion of the connector to see what would happen.

With my luck, I could visualize a meltdown of both the motherboard and the megabuck power supply.
 

StillLearning

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The fact that you are successfully using an ATX v2.3 power supply with a motherboard which is essentially the same as mine is encouraging.

If more people comment that they are using an ATX v2.3 PSU with an ATX v1.3 MB, I might be bold enough to try it on this unit.

I don’t have the wherewithal to pop for an entire new system all at once. Inasmuch as the PSU up and died on me, I started my piecemeal updating process with it.

Well, that what I thought I was going to do.
 

Sorry I left out " Deluxe " , yes it is a " Deluxe "

Plug the psu in, if there's a compatibility issue the system won't boot, it's not going to fry.

"Piecemeal" updating such an old system is kinda pointless, with the psu upgrade you've basically gone as far as you can, unless you're willing to upgrade to more powerful outdated tech ( more DDR , more powerful AGP video, faster socket 478 :ouch: )
 

StillLearning

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You have certainly given me hope. The unit I had been using for the last 5 ½ years (just six months past the warranty) was a Turbo-Cool 510 SLI. I looked up its specs on the Internet and found that it was an ATX v2.2.

I can’t see where moving up to a v2.3 be all that dangerous. I’ll do it tonight.

I have to leave now. I’ll get back to you tonight to tell you how it went.

Also, I’ll tell you my long range plan for upgrading. Maybe you can pull my butt out of the fire on that one, also (or, rather, keep me from getting in the fire to begin with).


 

StillLearning

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Well, I got home too late tonight to try to install the power supply.

But let me tell you something that happened while I was out:

The day I posted this thread to Tom’s Hardware, I also found an article on PC power supplies by a Mr. Mark Allen. I took a chance and sent him the same question posted here.

Lo and behold, he actually replied.

Here is his reply:

====================================================================================

“Oh hey. A P4C800-E deluxe. I had one in my main computer with a 3.2 GHz Pentium 4 many years ago. Nice to see one still running.

“The reason they're warning you about compatibility problems is because a newer PSU like a 750AX provides very little power on 3.3 and 5 volts. Corsair says it delivers a maximum of 125 watts on 3.3 and 5 volts. That's not much. Almost all its power is delivered on 12 volts. I do have a somewhat outdated page on this subject here: http://www.playtool.com/pages/psurailhistory/rails.html. One of these days I have to update that site. Basically, the newer versions of ATX deliver even more of their power on 12 volts and even less on 3.3 and 5 volts. The compatibility issue is really about which rails deliver which wattage. You can plug a newer ATX version PSU into an older motherboard as long as the connectors fit. It will work as long as it provides enough current on 3.3 and 5 volts.

“If the 750AX has 8 pin EPS connectors which split into two 4 pin connectors then you should be able to plug in that PSU in and try to run the machine. The motherboard manual doesn't talk about power requirements on its rails so I don't know how much a P4C800-E draws at 3.3 and 5 volts. That's a new enough machine that the CPU and a big video card draw most of their power from 12 volts. I'd think that the motherboard without much plugged into it would run fine on the 750AX. You'd get into trouble if you plug in too many things which draw much power from 3.3 and 5 volts.

“Personally, I'd plug the PSU in and try it. If the machine draws more than 125 watts on 3.3 and 5 then the PSU will just shut down. That's a nice PSU. It won't explode or anything. The overcurrent protection will kick in and it will be like someone pulled the plug. If most of the load is on 12 volts then it should run just fine. If it doesn't work then you'll just have to find a PSU which provides more current on 3.3 and 5 volts. It doesn't have to be ATX 1.3. A newer ATX version will work fine as long as it provides enough current on 3.3 and 5 volts and the PSU has the right connectors. Basically, that means the 24 pin main connector splits into a 20 and a 4 and the EPS connector splits into a couple of 4 pin connectors.

“You can get other brands of PSUs which provide 150 or 175 watts on 3.3 and 5 volts. You'll just have to read through lots of spec sheets to find them. You're likely to have to get a much higher total wattage PSU than you need. So if 125 watts isn't enough then you'll just have to shop around for an ATX 2.x PSU which provides more wattage on 3.3 and 5 volts.

“Mark Allen
comments@playtool.com”

====================================================================================

Ain’t the Internet wonderful? Now we know more than 99% of the people who make, install or repair motherboards and/or power supplies.

 

StillLearning

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Well, I’m back at Square One. Let me back up and start at the very beginning of this long saga and tell you the whole long story.

I was using PaperPort (which has always caused my PC problems) when the computer locked up. After waiting a while, I used Task Manager to exit the software. Next, I restarted the PC.

When the computer started, the welcome screen came up dimly and then, in just a few seconds, faded out. The fans were running on the power supply and the case (I did not think to see if the fan was running on the CPU), but the rest of the computer was dead. Repeated tries to start produced the same results.

I restarted and held down the Delete key to get into setup. The setup screen came up and then, in just a few seconds, faded out. The fans, etc acted the same as before.

I tried the C: drive with another computer using a Thermaltake docking station. It was fine.

I bought a COOLMAX 228 Power Supply Tester. The PG reading showed “HH,” which the instructions said meant it was so high, that it was off the chart.

So, I proceeded to order a new power supply – a good one - with the idea that it would, someday, be used in my new build.

When it came, I had a few questions about the cables. That’s when Ram Guy told me that the new power supply would not work with the old motherboard because the new power supply was a version 2.3 and the motherboard was a version 1.3.

I then sent out a request for help in a couple of support boards. One person responded that he was using the same motherboard as mine with a version 2.3 power supply and had experienced no problems whatsoever. Another wrote in and explained that difference between the two PSUs was that the version 2.3 PSUs provides much less 3.3 and 5 volt capacity than did the v1.3 units.

Both agreed that it would not harm either to old motherboard or the new power supply if I use the new unit. I first checked the new PSU with the COOLMAX tester. All of the readings were as they should have been. So. I did a barebones connection of just the PSU, the monitor, the video card, the sound card, the C: drive, the keyboard and the mouse.

What happened when I turned it on?

The welcome screen came up dimly and then, in just a few seconds, faded out, etc., etc. . . .

What could possibly be the problem?