URGENT HELP NEEDED: PC will not boot!

[Skrips]

Ok fellas, here is the scoop. A month ago or so i pulled the trigger on that new SB Z68 machine i was talking about in my other thread, some of you may remember. Well, now the damn thing is experiencing some very BIG issues. It started soon after i built it. First it did not want to power on once every so often. It would attempt to stat powering on, then fail, power off, then attempt to power on all by itself. It would do that for a while, maybe 3 cycles, then either boot up and post just fine then load into windows, or fail completely. At which point i would power it on again and it would usually boot up just fine.

Now the problem happens almost every single time.

To make matters worse, the machine sometimes doesn't want to power on at all, but gets caught in an infinite power on for a second then power off, then back on....will do that until i pull the plug and kill it. Sometimes i have to fiddle with it for 30 minutes until magically and for no apparent reson it starts working.

Then last night happened. Twice while i was modeling and rendering the machine just shut itself off. Upon reboot it posted fine, but the mobo displayed a message telling me that it had shut itself off to protect itself from power surges it detected from the power supply. I had one option to go into bios, at which point i did, then save and exit the bios and it worked fine.

One other thing to note, ive watched the power on lights on the mobo to see where it hangs, and ive noticed it always fails while powering on the cpu. That power light comes on, stays on, then the machine shuts itself off again and restarts the cycle. Always on the cpu. It never gets to the ram or the video card. A bad cpu? A bad cpu socked? But the thing that bugs me is that the machine works fine one its powered up. No warning lights on the mobo, and no other issues at all! If it were an issue with the cpu or the mobo, i think i would have other problems besides boot issues.

Ok, thats the rundown of the issues im having. Now here are the system specs:

2600K
ASUS P8Z68-V PRO
EVGA 580GTX 3GB
Corsair 850TX PSU
Corsair H100 CPU Cooler
Corsair Special Edition White Graphite Series 600T
G.Skill Ripjaw X Model F3-12800CL7D-8GBXH
Crucial M4 64GB
Western Digital Caviar Black 1TB

I am not running any sort of OC, mainly because i havent been able to reliably get the damn thing to boot without having problems. Ive checked all the power connections and components, short of reseating the CPU ive done everything i can think of. If it is the power supply, what gives? All the components i used are brand new, and once it is running it has passed ALL the torture/stress/stability tests i have thrown at it with flying colors. Simiply, it runs like a champ.

But i keep coming back to three potential problems:

Bad PSU
Bad CPU/Socket
Bad ATX switch on the case

Any ideas?

[Skully]

Reads like a bad PSU to me. Try a multimeter on the UPS, or try a different PSU.
Sometime it can be a short, try firing up the mobo out of the case. I've had
the 24 pin power connect short out. You can check that by just moving it
around a bit, while running.

[Skrips]

Don't have a spare PSU to use, and i don't have my multimeter here with me atm. But i am sorely tempted to run down to my local Fry's Electronics to buy a new PSU. Not excited about the HUGE line i know they are going to have today...

[Skully]

Reread the above post. I added a couple things. I'd really pull the motherboard out, and just run it with video, cpu, and memory.
To make sure your not getting a short from the case.

[Skrips]

Removing the mobo seems a bit extreme. I can safely say that i am 99.9% sure its not shorting out on the case. That leaves mobo/cpu, or psu. And im still leaning toward the psu unless someone can come up with some compelling idea.

[Skully]

Removing the mobo seems a bit extreme. I can safely say that i am 99.9% sure its not shorting out on the case. That leaves mobo/cpu, or psu. And im still leaning toward the psu unless someone can come up with some compelling idea.

Ah not that bad, as long as you set the mobo on an Anti Static Bag, or the box it came in.
I'd do that as a last resort. First the PSU is the one I'd check-out.

[Wendy]

I would try clearing CMOS. You would be surprised how many issues this solves on the new Intel chipsets regarding power management.

Once you've cleared CMOS, redo your settings but don't set an overclock for the moment. If your running Windows, allow the PC to boot fully, then run the Windows Experience Index which will update various tables in CMOS, then reboot and see how things go.

[Skrips]

I already tried cmos clearing a week ago when this started becoming a real problem. I cleared it and redid all my settings. Still have the problem. Also tried all the standard stuff, including trying one ram module at a time. Still the problem persists.

So, i still come back to a psu problem as the most likely cause....

[Skrips]

Update: i just went to frys and bought a Corsair 850AX. Will be installing it soon, and will update again after im done.

[Skully]

Hope to hear the new PSU fixed the problem...

[Skrips]

UPDATE: OK, so I worked on it last night as I said, and ripped out the old PSU when I got home. I installed a brand new Corsair AX850 modular PSU, and guess what? The machine booted up just fine the first time, no issues. I wanted to wait to update this post so I could check it again this morning after leaving it sit all night, and it booted up the first time with no issues this morning as well. So ther eyou have it: a bad PSU. Of Course, this could be just a temporary or apparent fix, and it may very well start showing the same boot errors again, since they were some times intermittent to begin with. Time will tell!

Thanks to all for the help, and have a great holiday season!

--Skrips

[dctokyo]

To make matters worse, the machine sometimes doesn't want to power on at all, but gets caught in an infinite power on for a second then power off, then back on....will do that until i pull the plug and kill it. Sometimes i have to fiddle with it for 30 minutes until magically and for no apparent reason it starts working.

Happy to hear that the you got it working again ................. About your quote above, I would say that 9 times out of 10, the problem lies with a bad PSU.

[Skully]

You're welcome...
Well I hope its the cure to your problem. At least its looking good so far...

May you also have a great holiday season!

[PiLsY]

If its the original TX series then they have problems and are dropping like flies. I used to use these in builds for people - Ive had to rma 3 x 650tx, 2 x 750tx and 1 x 850tx. All exactly the same - starts with instability of the PC and ends with the PSU going pop, all have been 2 to 3 years old. They ship the replacement as soon as they receive your dead TX rev 1 unit, had mine arrive direct from china in 5 days. Warranty is 5 years on the TX.