# First build, power supply won't turn on, but motherboard is lit



## pattamus (Oct 26, 2008)

(posted in this forum because I'm pretty sure it's not the PSU failing)

Hi,

This is my first custom build. I took hours to connect everything, had everything pretty(wires tied with zipties), and thought I was ready to go. Well the power supply wouldn't turn on. The motherboard does light up when it's plugged in, but turning the power on doesn't do anything at all that I could notice. It's definitely not dead, because I'm using it right now. I took parts out of this PC to put into the other one. Power supply is a BFG 650w. The other specs are q9400, asus p5n-d 750i, patriot viper ram(2 x2gb), and 2 8600gt SLI. I tried with just one card, so it's not the SLI. 

I had lots of trouble with the heatsink(arctic cooling freezer 7), it just didn't want to go. I turned all the screws the direction told. I did finally get them all down. I ended up taking it off and installing the stock heatsink to see if that would do anything. All it did was make it near impossible to re-install the arctic, and some of the connectors got bent from me trying to force it. I bent them back with pliers and they should be fine for the next time, I sure hope so..

Any usual culprits for this that I may be overlooking? The case I bought has the PSU slot at the bottom, so I had to make the wires from the PSU stretch to make it to the CPU power slot. It did make a firm connection though. I read alot about hooking the fans to the motherboard connectors, and saw a bunch of fan connection slots. All the cases fans just had power connects, nothing to connect to mobo. The only one I could use was the processor fan slot that connects to heatsink. All the other fans just had power connectors. Is there something I'm missing with the fans possibly? 

Another quick question, I have vista OEM from dell on this computer, and I have the disc for it. I'm planning on installing it on the new pc. Will it give me 30 days to register, or will it recognize it's not dell BIOS and not let me install? I can get a new OS soon, but I wanted to use this just for now if possible.

As you can probably guess, I'm pretty let down that I couldn't get it working no matter what I tried. I had to take it back apart in defeat and put parts back into the old box so that I could try to figure this out. I'm new around here, but when I get this thing going I certainly wouldn't mind staying around to help someone else possibly. Thanks for reading, and I appreciate any help!


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## Tumbleweed36 (May 14, 2005)

Did you remember to connect the +12 volt molex connector? Also, you might want to pull the two off/on wires from the front panel header and then take a screwdriver or paper clip and short across those two pins to see if the switch is bad. If the switch is bad, it will come on if the power supply is plugged in and on. Don't hold it on there, but just touch the two pins to see if that might be an issue. I know it is a new case, but that happens sometimes and you get a bad case switch. Have seen that in my shop several times.

As I read this, you may need to bench test this thing if things don't improve:

Bench Test Your System


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## pattamus (Oct 26, 2008)

Hmm, 12v molex, i'm not sure on that. The mobo came with a piece that connected all the really small connects and made it into one. It had small letters on it and I'm pretty sure they matched where I put them. Don't remember a 12v in particular, but could it have been one of those?

What are the chances my processor isn't connected well to the heatsink or I just installed it sloppy? I did the best I could but I don't know how finicky these things are. I've been reading to connect the CPU power to mobo, does the heatsink/fan switch cable to mobo count for that? I also had power from the PSU to the mobo and cpu but I can't remember CPU to mobo power connector..

If I can't find a simple solution, or something I just simply overlooked, I will definitely try the bench test when I wake up (been up for awhile with this thing). Thanks for the help :smile:


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## Tumbleweed36 (May 14, 2005)

The molex connector is a little square connector (most 4 wire) that has yellow and black wires in there. It connects to the motherboard to provide power.


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## pattamus (Oct 26, 2008)

EDIT: I've just taken a look at my heatsink/fan, and it has the small connector shown in the pic and it was connected at the time of my problem.

Ahh, yes I've hooked up several of the "big" ones. Each fan requires one, maybe some other hardware too. Each one I saw in the case, I hooked it to power. As far as the "little" version, I don't think I connected any, but I'm not positive. Here's a pic of the little one I'm talking about :









For the drives, I used SATA connectors to the mobo, and SATA power from the PSU. Even the dvd drive. I did connect a 4-pin CPU power plug with a plug that looks different than those. It has the 2 connectors on top and 2 on bottom, and a clip. Does the fact that I didn't hook up CHA_FAN1 or 2 another fan slot that was empty? I did get power to them straight through the motherboard. There was no cable to plug them into such spots.

Also, did anyone know anything about the OEM (dell) version of windows, as far as it's ability to install on a different system, at least for 30 days while I get a new OS? I can't run out and buy a new OS right this second. Especially considering the costs I just paid for all these parts(which aren't even working :upset.

Thanks again for the help


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## Wrench97 (May 10, 2008)

If it's not a dell then it won't activate.
You should have 2 power connectors from the power supply to the motherboard a 24 pin and a separate 4 pin without these it won't post.


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## pattamus (Oct 26, 2008)

Yeah, as far as the dell OEM vista disc, I figured it wouldn't ACTIVATE, but I'm hoping it will let me install and give me 30 days to register. By that time I'll have a new OS. I would be in trouble if it won't let me install the OS at all. That would be a problem.

Well, I've been busy with work related things, but tomorrow i'm gonna get on the ball and try few more things. If I cant get it to fire up, i'll use that bench test that I was linked to and find the weakest link of the system.. I sure hope its not the CPU because it only has a 7 day warranty on it. If it's the mobo, then i'll have to RMA and get another SLI board which will be an upgrade of course. Can anyone reccomend a SLI board in the price range of 135-175$? maybe go 780i instead of 750i?

I'll be back soon with my results, wish me luck! And thanks to those that helped:smile:


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## dai (Jul 2, 2004)

bfg is not a recommended psu you also need a 750w for running the sli
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006&Tpk=corsair+750w


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## pattamus (Oct 26, 2008)

Ok, so I did the bench test. It wouldn't fire up with the most basic parts mentioned in the tutorial. I have 3 different kinds of RAM, tried all. Two graphics cards, tried both of those as well. Also, two different heatsink/fans.The motherboard light turned on with the power, and as I was holding down power button(on the case) the processor fan and case fans would spin.(at first I didn't attach case fan, but then tried after I got nothing) Just for a second though. . Like I said before i'm using the PSU, ram, Hard drives, dvd, and graphics card from this current pc, and they are all working well(I didn't use anything but the basics, just clarifying that they do work).

As far as needing 750w, The guy who sold it to me was running it with these same vidcards and similar quadcore. Some guides I read said it would be enough, and I just figured since he was running it fine that it was okay. I'm sure you know more than I do, so i'll take your word that I probably need more. But with the basic bench test, 650w should have worked for sure right? 

Anyone had this kind of thing happen? If you could tell me the most likely culprit, I can RMA and try again. I'm thinking of just RMA the mobo and get a 780i series. But i'd hate to get my new one and this same thing happen.. I've put too much into this to afford some tech to look at it then tell me I need to pay him 200$ plus having to replace some other part...:sigh:


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## pattamus (Oct 26, 2008)

No one knows what could make the fans spin for a second when first turning it on, then turn off? Is it just a bad motherboard? I really need to know before I return it.


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## Wrench97 (May 10, 2008)

Do you know what Bios version is on the board? The Q9400 needs version 0701
http://support.asus.com/cpusupport/cpusupport.aspx?SLanguage=en-us&model=P5N-D
Do you have an older CPU to try in the board?


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## pattamus (Oct 26, 2008)

That is an interesting idea, and it does make sense. On newegg they were all saying to update the BIOS as soon as you get it, and also in the manual it tells you to do it first thing. It sucks if they would ship this thing not supporting current chips(it's not even that new). 

I guess the only way to update it would be to put another CPU in there. Is there any way to find out the BIOS version without doing that? Would it make more sense to just return it and get something better? That's what I had in mind, but if I can make it work I will. Also, do you think it's pretty certain its a motherboard issue? I'd feel better if I knew that's all it was. If you think the BIOS is the issue I can put another CPU in there, but i'm scared to ruin this computer trying to fix the other. I've already had problems putting this thing back together.

Thank you for the reply and help :smile:


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## Wrench97 (May 10, 2008)

All depends on how long the board sat around before it shipped or was sold, 0701 is not the latest but close enough to be the problem, see if you can find a supported celeron or P4 around and give it a try, If it boots then you'll know Asus tech support should also be able to tell you what Bios version it is from the serial number.


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## pattamus (Oct 26, 2008)

Actually, I do have an old p4 sitting around I can try. Didn't even think about it running that. I also have a core 2 duo in this box which I'd rather not try, but will if it's necessary I'll try it as my last resort. 

Do you have an opinion on my power supply not being sufficient? It's a 650w, not the best brand, but I thought it would run my SLI setup(2 8800gt) at least for the time being.

Also, someone was talking about pressing a screwdriver on the power slot, do they mean touching the 2 pins on the mobo that correspond to the power sw? Because the actual power sw cable coming from the case is female of course. The case has the power button at the top, and it doesn't slide off. Was gonna try that as well.

Thanks again, I'll wait your reply and then try this thing one more time.


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## Wrench97 (May 10, 2008)

If the P4 is on the supported list then pop it in.
You know what they say "If you don't have anything good to say about a PSU don't........."
650w will SLI 2 8600gt's if I read that right but I'm not sure you'll get the desired results from them as they don't scale real well.


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## pattamus (Oct 26, 2008)

Nah they are 8800gt's rather than 8600. I'm glad I now know the PSU is trash because the guy that sold it to me made it sound good of course. 

If I get lucky enough to get this working, I will replace the PSU by christmas. If not, I will RMA this board and leave you guys alone. :wink:

Hopefully i'll be back with good news, if not, I hope I'm not back again with problems when the new board arrives!


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## Wrench97 (May 10, 2008)

2 8800's at least 750w.


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