I've got a weird problem with a system I've just built for someone. If the system has been turned off for an hour or more, you have to flip the power switch on the PSU from the On position, to off, back to on again and then it boots just fine. If the computer is turned off for less than an hour, it's fine and you don't have to do this. It's like when the computer's been off for an hour or more, the power drains from the system and it's like you've turned to power switch on the back of the PSU to off, when if fact it's on. Any ideas as to what is causing is and how to fix it?

Here's the specs to this computer: A64 X2 4400+, MSI K8N Neo4 Platinum, 2GB of Corsair ValueRAM (4 x 512MB), GeForce 7800 GTX 512, Seagate 400MB 7200 RPM IDE HD, Lite-On 20x Burner and OCZ GameXStream 850 watt PSU.

Is this a new PSU?

Check the connections between the PSU and everything. Check the connections between the case and the MOBO header.

Yes, it is a new PSU. I'll recheck them though. I also posted this question at the MSI forums and one guy suggested that it...well, let me just post the message below: "It appears that for some reason the +5 volt (+5v VSB) power good signal is being interupted until you recycle the Mains switch. Most likley the problem is in the PSU itself as this is where the signal is generated, but it is possible that the signal is being interupted at the motherboard. Try a different PSU or RMA the PSU first as this is the most likely suspect. If that doesn't fix it then you have a motherboard problem.
+5v should also power the USB optical mouse if you have one, does the light remain on after computer shut down? It should. If after a while it shuts off that is an indication that you have lost the +5v power. You may also be able to check this with a power supply tester. The 5VSB line (Pin 9 of the Mobo Connector) should have +5vdc power whenever the mains switch is on and the power supply is plugged in." http://forum.msi.com.tw/index.php?t...

I'll try what you suggested though...sigh. I'm not looking forward to ripping out the PSU and installing another one. I was going to suggest that he might keep this one but then I'm being selfish and lazy. I like my work to be perfect and because of this, it's not so...that said, I think I'll suggested either the PC Power and Cooling Silencer 750 watt PSU: http://www.newegg.com/Product/Produ... or the Corsair 620HX PSU: http://www.newegg.com/Product/Produ...

That is a pretty pricey PSU. I'd try a different PSU. You don't have to totally remove it. Unplug it from the MOBO and from whatever drives you want to run. You can set a different PSU along side the case and plug it into the MOBO and drives.

You don't need 850 watts for that computer. I built one with 2GB 6400 RAM, an ASUS M2N-SLI Deluxe MOBO, an Athlon X2 5200+ 2M CPU, and an ATI Radeon X1600 PRO 512MB. A 600 watt Ultra PSU ($70 at Fry's before rebate) works just fine.

I have one PS that is picky about how the wiring bundle to the main connector approaches the connector. If the wires near the connector when plugged into the mboard are at a sharp angle the computer won't boot reliably, but if the wiring bundle approaches the connector at a more gentle angle, the PS boots the computer fine.

Make sure all the metal ends on the wires are securely locked into the main connector from the PS, as in, they don't move away from the mboard connector when plugged in.

If you have any suspicion the power switch is defective, which is rare, if your case has a reset switch it is the same type of switch (momentary - on only when pressed) - try the reset switch wiring connector on the power switch pins and use the rest switch as a power switch.

The circuit that responds to power good on the PS can be defective even on a quality PS. My brother had an Antec that had to be RMAed because that was defective on his.
Try another PS. If you then have no problem, RMA your PS.

"I have one PS that is picky about how the wiring bundle to the main connector approaches the connector. If the wires near the connector when plugged into the mboard are at a sharp angle the computer won't boot reliably, but if the wiring bundle approaches the connector at a more gentle angle, the PS boots the computer fine."

Why do you think that is?

Re: Tubesandwires

That's odd that you should say that because there are two different spots marked on the mobo for the Power LED. One of them is supposed to be for and Intel mobo...at least that's what it says in the book, but then why did they even mark a second set of green indicator spots if that's the case.

The PLED where I think only has two pins, but the other spot, under the Speaker connector has three pins, but the PLED connector only has two pins so one would think it would go in the two pin connector. At any rate, I've tried both and when I've plugged the computer back in after messing around with these, it often turns on immediately when the switch on the PSU is on. It shouldn't do this obviously and only come on when the power switch is on of course but only when you push the power button on the front of the case. So I think you may be onto something here.

What's so annoying about this whole thing is, that to test to see if a particular change works, I have to wait 2+ hours to see. Before I believe I said and hour but I've seen it work after that, but it really sux that you don't know if something works unless you shutdown the computer and wait for 2+ hours to see...with the power switch on of course.

Now, I've put my old PSU in and test to see if it's the PSU because this mobo and PSU didn't do that at all before. I've sold these parts to someone else...that is the vid card, mobo, CPU and RAM. The only new parts are the PSU, HDD and optical drive and the case. Now, I've put my old PSU in to see if it still does it. If it does then it's got to be the case or some grounding problem but I'm almost 100% sure I've not left any metal risers touching the underside of the mobo. Anyway, if that was the case, I don't think it would be so predictable and the problem would only surface after 2+ hours.

I'm hoping it's the switch like you said. Anyway I'll know if this old PSU fixes the problem or not...after I play the waiting game....sigh.

If you have a manual with the pinouts in it, go by that. Labelling on the mboard beside the pins can be confusing.
There are always two pins for the power switch and two for the reset switch and two for the hdd led. There are three pins or pin positions (middle pin may not be there)on the mboard on a standard front panel header for the power led, and almost always two wires on the ends of a 3 position female connector from the case - a few cases have only a two position connector for the power led.
The pins for the power led have nothing to do with the power switch, or whether the mboard will boot or not. They and the hdd led pins, speaker pins, etc. other than the power switch pins don't have to be connected at all for the mboard to boot, and either the power led or hdd led works if the connector to it is installed in the right direction, or it doesn't if it is backwards.
Many mboards that are used both in retail mboard manufacturer's models and in brand name system builder's models have an alternate header or headers for a case connector or connectors specific to the brand name system's specs, often to conform to a one piece front panel connector's wiring. If there are pins on both, you can connect to either header(s).

On many more recent mboards you must have a 3 wire cpu fan connected to the proper cpu fan header on the mboard - if no rpm is detected from that header the mboard may shut down after only a few seconds.

Once you are certain you have everything on the right pins, and you have a cpu fan connected to the proper cpu fan header on the mboard, trying the old PS if it has enough capacity is a good move.
If nothing else is wrong the PS that was on it is probably defective.

Doctor1954

Regarding your response 5 I answered that yesterday but must have neglected to Confirm the post.

I'm not sure. Maybe there is a metal end terminal on a wire that has a slightly loose connection that makes an okay connection only when the wires are not sharply angled?

Well guys I'd like to thank you for your help. As it turns out the new PSU was bad. I'm not sure what's bad on it, but it was bad because I put my old one in and waited 3 hours and it fired right up! I've tried to do that with the new one and got nothing, sometimes after even one hour. Anyway as it turns out my LED connectors were right on the money the first time. It just made me doubt myself not knowing what the problem was.

I knew it wasn't the mobo because I didn't have this problem before so I thought it had to either be the PSU or the case...maybe something to do with the LED connectors. Oh BTW, this case only has a 2-pin LED connector...go figure. It is confusing though but now that I know what the problem is, everything is fine. I decided to give this PSU to my client. It's good and I don't need it because I'll be being a Corsair 620HX PSU for my Quad core Q6600 system with either a Radeon X2900XTX or a GeForce 8850 GTX...whichever one is faster and/or comes out first. Anyway, my old 535 watt Enermax PSU doesn't have enough juice to power what I want....especially if I get the new R600!

Again, I'd like to thank you guys!

It's good to hear you have solved the problem!

"...I put my old one in and waited 3 hours and it fired right up!"

You should not have to wait at all.

"this case only has a 2-pin LED connector..."

If your power led isn't working, if the 3 position power led on the mboard has three pins sometimes two are grounds and the two position connector from the case will work on tweo of the 3 pins, or there may be an adjacent pin to one or the other end of the 3 positions that is not used that is ground that you can use aslong with the + pin in the 3 positions.

"Anyway, my old 535 watt Enermax PSU doesn't have enough juice to power what I want....especially if I get the new R600!"

That is a lot more capacity than you need for any single PCI-e video card - if it isn't the new PS that won't boot reliably, it will work fine. I use Enermax - they are excellent PSs.

Thanks, I feel so relieved! Anyway, my PLED is working fine, I just wasn't sure if I putting it in the right place because believe it or not, it works with the other spot too!

I wanted to get a PC Power and Cooling Silencer 750 Quad PSU but I don't have $200, so I'm gonna settle for the Corsair...it has enough juice for at least this upgrade I'm doing now, but I've got to say, I'd love to get the PCP&C PSU! I think those PSU's are the one of the very best if not THE very PSU's you can buy. Actually, I'd like to get the 1K but money dictates what I get and I don't have that much. I get to upgrade bi-yearly and this year is my year so I've got to get the best parts I can.

"..believe it or not, it works with the other spot too!"

It will if there are pins in both places.

As I've already said, if the Enermax is not the one that you were having the problem with, it will work fine. PSs of the capacities you are talking of are a gimmic - you don't need them.

Well with the new R600, I've read rumors (all are rumors since it's not released yet as you probably know) that it will use between 200 and 300 watts...that's just for the video card alone! It looks like though that it might really use about 240 watts. That rumor seems to persist the most. I thought my Enermax would be OK but then as someone said, do you really want to take a chance frying all your components? So I'd rather be safe than sorry...ya know. Also, I'd to have a PSU that will last through many upgrades and at least this Corsair 620 watt PSU should last for this one and at least one more. It all depends on the power draw the CPU and vid cards are requiring in 4 years to be certain though.

I'll put it this way. If your mboard does not have PCI-e slots at all, a 350 watt PS will handle any mboard with any cpu with the ram loaded to max capacity. I have never heard of any PCI-e video card needing more than about 45 watts, and even if you have two in SLI mode, that's still only 90 watts. I am extremely doubtful there would be a jump from that to 200 to 300 watts.

I do have a PCI-E mobo and the GF 8800 GTX uses 180 watts....this is documented. Still, my PSU could probably handle the G80 or the upcoming G81. The R600 which like I said is rumored to use between 200 and 300 watts would almost certainly need a high wattage PSU to feed it. The wattage of the Core 2 Quad Q6600 uses 105 watts...which is a little less than my current A64 X2 uses actually. Still using a PSU calculator, I'm still good if I used the same 535 Watt Enermax PSU, but I'd rather be safe than sorry!

Sorry, I meant a GF 7800 GTX 512. I don't know how much it uses but I know it's more than 100 watts. The high-end cards always use up allot of wattage and starting with the G80, they're nearing the 200 watt mark which the R600 could easily break. The good news is both ATi and Nvidia are pursuing multi-GPU cards. I'm not talking about like Nvidia's GX2 series but multi-cores like with the A64 X2 and Core 2 Duo and Core 2 Quad procs. They are supposed to use around 30%+ less wattage than current single core GPU's do. Of course games will have to support these multi-core GPU's, but you know single GPU design is soon to be a thing of the past, just like single-CPU design soon will be.

Very soon there will be some dual core CPU's that will go for under $100. I imagine in the next 4 or 5 years, Intel and AMD won't even be developing any new or current single core CPU's as multi-core is the future!