Computer Cycling On & Off

[tracerbullet]

I'm having a similar problem to somehting posted a few weeks ago here: http://forums.anandtech.com/me...id=32&threadid=2117050

That user had one post and hasn't replied back to it or yet to my PM.

I've had a new rig running several months, Q6600 with an 8600GT, 2GB RAM, 2 DVD burners, 3 SATA hard drives (2 are WD Raptors), and.. that's about it. Rosewill 550W Power Supply. Always been connected through a 1200 VA UPS.

It's been fine for months, I've beat it up quite a bit, never had a problem. Tonight I had it on for about 10 minutes, just surfing, and it froze up. I rebooted, but it couldn't quite get into Windows without freezing again. So I turned it off altogether, and ever since it hasn't really quite restarted. It tries but can't.

When I hit the power button and it begins to fire up but not quite to POST, and after several seconds it shuts back off. Give it about 5 more seconds and it tries to start up again on it's own. Then shuts back off, starts back up, and repeat and repeat. I've pulled almost everything from the board - the RAM, all drives, and the video card, and still have the same issue.

I got the gist from the other post that the PSU for his (which was 480W) may not have been enough. I have a lesser video card, but possibly more drives. Going through the supposed power draws I shouldn't be but about halfway to that 550W or so. And - even if it wasn't enough in the past then - with everything unplugged it certainly should be enough now!

This is my first Intel build, I am wondering if the CPU would throw itself into some sort of cycle perhaps by telling the motherboard to shut down because it thinks it's overheating or something? Or do I start with the PSU? I don't have hardly anything attached to the Mobo right now, but I suppose it's possible that it's gotten damaged?

ANY HELP IS GREATLY APPRECIATED! THANKS!

 

[DigitalWanksta]

Is there anyway you can get temps off your CPU? Also, is it doing this even after you have it shut off for a significant amount of time? If the temp. is not the problem, I'm thinking a bad sector or damage on the hard drive (main) where windows is booting from.. Another option to try for shits and giggles would be inserting you OS CD and seeing if it will boot from the CD..

Just a few things to try.

 

[robisbell]

can you get a a multimeter and test the psu, I have a feeling it may be a faulty psu.

 

[tracerbullet]

Awesome, such fast replies!

In answer to the first post, no, I can't get temps of anything. It's only started for a few seconds, not even into POST, before the power shuts itself back off. And yep it still does this even after sitting for several hours, I was hoping it was actually heat but apparently not. It can't even attempt to get to the hard drive or DVD drive to even think about booting the OS.

Robisbell, yes I have a digital multimeter. I "get" basic electronics (12V car and 110 household) but don't have any idea what to look for in a PSU. Help along those lines would be great.

 

[robisbell]

http://www.ochardware.com/articles/psuvolt/psuvolt.html

http://www.metacafe.com/watch/...ters_power_supply_psu/

 

[tracerbullet]

Everything checks out.

Pulled the main connector from the mobo, jumpered the green "on" wire to ground, flipped the switch in the back of the PSU to on, and it fired up and stayed that way. I read 3.37, 5.07, and 11.98 everywhere that the 3.3, 5, and 12 were expected. All wires in the 20 pin connector, also the 4 pin connector, also at the wires that lead to the drives.

Plugged it all back into the board (20 + 4), plugged back in the drives, etc. (no jumper though) and hit the power button on the front of the PC. It still cycled as expected, and the voltages were all the same, still 3.3, 5, and 12. (was really hoping they'd drop a lot but no such luck).

For the hell of it I unplugged the wires from the power & reset switches, the little ones that go to the mobo, just in case I had a bad switch. Nothing there. Just touched the power pins with a screwdriver tip and of course the PC turned on. Still did it's cycling thing though.

So... motherboard or CPU are the only things that haven't been yanked at some point, and that could be contributing. It appears that the PSU is delivering.

 

[robisbell]

okay, if you can pull the board and try booting it outside of the case.

 

[tracerbullet]

I'll give it a shot but it will be tomorrow. More than I'm ready for right this minute. Thanks for the help thus far, I'll be back with my results.

 

[Tpain]

GL!

 

[UndrMediKated]

Clean your CPU and heatsink.
Try unhooking all your hardware you don't need to boot up with and run it that way.
Also, try another power supply. I've had the same issue with that also.
Bad RAM will do this. Try using one stick at a time.

 

[UndrMediKated]

Your power supply is big enough.

 

[tracerbullet]

Not sure what you mean by cleaning the CPU, but - the heatsink and etc inside the case, everything is spotless. This isn't turning off after a while from overheating, it's cycling every couple seconds even if it hasn't been run for a few hours. Tried RAM 1 stick at a time, alternating between them and with both and with neither, no change.

Board is out. CPU, RAM, and heatsink are attached, and the PSU plugged into it, all 3 spots (20 + 4, and the other 4 pin near the CPU). Nothing else whatsoever. Still cycling on and off.

I'm guessing it's pretty much down to being either the board or CPU?

Time for some turkey!

 

[robisbell]

I'd go with the board.

 

[tracerbullet]

Just to follow up, I brought the board, CPU, and a memory stick to a local sales / repair shop, was just $30 to diagnose, kinda nice. They pulled some stuff off the shelf and swapped a few things out and it's definitely the motherboard. Looks like RMA time...

Thanks for the help! It was good to at least get it narrowed down like that.

 

[robisbell]

glad you did, and let us know if we can do anything else to help.

 

[mattbesquare]

Thanks for the information everyone. I too had the exact same problem. I swapped every component (every cable, power supply, monitor, ram video, etc)into my mother board and it failed to post, just cycled power on and off. I searched the web for help and only found what I needed here....after many many many hours of swapping.

I will update you guys to let you know what happened after I swap my motherboard this afternoon.

And regarding the powersupply conversation... A Antec True Power 2.0 380 watt power supply can power an intel E6750, GTS8800 Superclocked, 2 gigs of ram, and two Sata 250 Gb HD's. I did this for many months before getting an new PS so I could use the second 8800 in sli mode. The Watt rating of the power supply is important, but more important is the stability of the voltage. Most of the cheap 600-1000 watt power supplies cannot supply a good solid voltage and compensate for a current drop (plugging in an iron on the same circuit) that a lower wattage higher quality component can...imho.

Regards