New build will not POST.

Just put together a new machine with an ASUS z68-v/gen 3 board and an i5 CPU but it will not POST. Tried disconnecting the drives and leaving in only one stick of RAM with no luck. Traded MOBO in tonight with no change. Any ideas or suggestions no matter how basic would be appreciated.

Thanks

Power supply?

Are you getting any indication of power? Beep codes or anything? Maybe a bad power supply?

Describe the symptoms better.

Then I can give you more useful info.

Sorry guys. Give it power and the power supply comes on, the cpu fan runs and the LEDs on the board come on and then go out. At about 3 seconds the cpu and power supply fans stop and the "power" switch on the mobo stays lit but has no effect when you push it. No beeps at all but I don't see a piezo or any other speaker on the board.

correct power adapters plugged into the video card?

No seperate video card. Chip has video on it.

Later I will open a running machine and use the PS to try to get the new one to post. The new build has a Corsair 550 in it. Would suck to see it DOA but it happens I guess.

the beep codes will tell you what is wrong. Is there a speaker mounted in the case? If so, plug it in to the MB

I had several issues with the Z68 chipset on my latest build, I'm not fond of it, took my switching from Gigabyte to Asus to fix it. Though I had a different motherboard, it seems that Z68 is very susceptible to BIOS corruption. That said, if you've swapped out the board and it is doing the same thing, you need to check the memory and your CPU. If the lights on the mobo are coming on, as well as fans, things are likely plugged in correctly. Did you make sure to plug in the 4-6 pin connector in addition to the 24 pin connector on the mobo?

Pull ALL of the memory out, see if you get a beep code then.

Remove the CPU, inspect the pins in the socket, and reseat. I have seen sockets come from the factory with a pin bent.

I have tried to post with no RAM. There does not seem to be a speaker on the board which is odd but I don't see one. 24 pin and 6 pin are both plugged in.

This.

I had a metal standoff ground a MB to the case one time. Make sure you don't have that problem.

Tonight I got a new chip, Tried it with a video card, tried new PS and cord, Pulled the MOBO free of the case and tried to fire it, Shorted the clear BIOS pins (with the batt out). Tomorrow I will get a speaker and see if it beeps or not, also plan to bench POST with the CPU but I have never done it before. Have to figure out how to short the thing the right way. Keep the ideas coming.

Metal standoffs always short the motherboard's ground planes to the case. I even know a guy who cut all of the ground wires on the plugs going to the mobo, and let all of the current return via the standoffs and chassis.

If your standoff was causing problems, it was not just grounding the internal planes, but something else as well.

Anyway, OP: Can you give us links to the RAM, mobo, and CPU that you are using?

Maybe it's the "on" switch on the case. The PS switch should cause the "standby POST" where you get a little fan movement and the standby LED on the motherboard "power applied". Then closing the switch lead that goes to the front of the case gives it the soft boot from there.

In high school I knew someoen who didn't know you had to use standoffs on the motherboard.. he fried a couple before he figured it out

http://www.microcenter.com/single_product_results.phtml?product_id=0378096

Board


http://www.microcenter.com/single_product_results.phtml?product_id=0354589

Chip


http://www.microcenter.com/single_product_results.phtml?product_id=0364400

RAM


Sorry it is not hot guys. Thanks for the input.

When you tried it with just 1 stick of RAM did you make sure it was in the A1 slot? Did you try each stick separately in that first slot?

Edit: Section 2.2.6 in the manual shows a bunch of status LEDs on the motherboard. Are any lit up when you try to turn it on?

I have tried one stick of new RAM and one stick of old from a running unit in that slot.

The LEDs come on and flash off and then it dies about 2.5 seconds after the power is turned on. NO LED stay lit. I am going to Fry's to get a case speaker in a bit. Will report back. Do you have a technique to make the PS come on w/o any switches? I am thinking that should be the next step but I have not had time to research how to do it w/o letting the smoke out of the board. Thanks again

There should be 1 green wire in the big ATX connector. If you short it to a black ground wire the PS should come on. A paperclip works well for this. I also saw in the manual there is a little power on switch on the motherboard. Have you tried that instead of the switch on the tower?

Try a different power supply.

, I have tried another PS

The switch on the board glows but has zero effect when there is power to the board and you push it. It does not go out until the power has been turned off at the power supply.

I have had this happen with PSU's that for some reason were not compatible or were defective.

There are two possibilities when the PSU is powering up, then powering down shortly after.

The most common is that one of the various protections in the PSU itself is causing it. Short-circuit, low line voltage, high line voltage, or failure to enter regulation. Short-circuit (self-explanatory) or failure to regulate (failed components, usually capacitor) are the most common. Because it will wait a second or two trying to get regulated before shutting down, that can be the cause of the delay. They can also do soft-starts, which make shorts take a second or two before the PSU shuts down.

The other is that the motherboard itself is de-asserting the PS_ON line. Usually, that's because one of the POL converters on the motherboard (like the one that feeds the CPU) has encountered the same sort of conditions. Since some of the mobo doesn't get powered up until the PSU sends the PWR_OK signal, that can be the cause of the delay.

If you've tried a known-good PSU, done it outside of the case, verified that the pins in the socket are not bent or misaligned, tried known-good RAM, etc., then it's likely a bad motherboard.

RESOLVED!!! The power switch on the CASE was wired ass backwards. I went to buy the speaker and while putting it in pulled the wire block off and then the phone rang talked for a bit and then tried to turn the machine on BEFORE I put the wire block back on the board. Fired right up so I killed it and added case wires back to the board and rePOSTED every time until it would not turn on. The on switch polarity was switched. I guess I should call Micro-Center and tell them the MOBO and chip-set I took back are really okay. Shithouse luck for the win! Thanks everyone that posted!!!!!

I know you guys were really going out of your way to help me and I can't tell you how much I appreciate it. I know how the pieces go together but some of you guys are phenomenal in your understanding of how this stuff works my most humble thanks.

Welcome to the Hive my friend.

back in the day we used a flathead screw driver to turn on breadboarded motherboards... shrug


i can't recall anytime where switching the wires would cause this.. but i've been wrong before

I know that switch is supposed to just be a momentary that "shorts" the power supply making it come on but it would work one way and not the other. No good explanation but I will take a working machine over a paperweight. 8 gig of RAM running at 3 Mhz loads stuff a lot faster than the 1.09 Ghz with 1 gig that Dad was relagated to. Now I need a first person shooter to play. Any suggestions there?

Battlefield 3, but onboard video might not suffice for it.

Frankly, I do not, and have never, liked the industry (non)standard method of connecting the switches to the motherboard. Some are polarity sensitive (as you've seen)
and it's not difficult to incorrectly configure all those cables on that group of header pins. There has to be a better way.

And there is. The machine I just got done building for work is built on an Intel S5000PSL server motherboard with matching Intel server chassis. All the switches and status LEDs are connected via a single ribbon cable and connector to a matching header pin group on the board, and it's keyed so you can't connect it incorrectly.
(Nice machine, BTW. Dual quad core Xeons at 2.5 GHz, 16 GB of RAM, and 2.4 terabytes of disk storage.)

The industry should standardize on this system of connecting the board to the front panel switches and LEDs. It would save a LOT of headaches.


CJ

The motherboard industry has had a nearly uniform pin block for years. It is the case manufacturers that lag behind in making the block connectors.

Case mfg would have to standardize also, and i don't think they want to...

Well, they standardized on board mounting patterns. To a point, anyway. Some cases are more versatile for mounting
various mobos than others. The best of them have a mounting plate full of every possible ATA spec screw position, and
include a bag of threaded standoffs that you insert where needed.

Really, unitizing the control cable assembly shouldn't be a big deal.

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