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CPU_LED and DRAM_LED lights flashing back and forth

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December 27, 2012 6:29:34 PM

Hello,

Embarrassingly enough, this is my first time trying to build a PC. I'm a software developer so have never really had to worry about hardware before and figured this might be fun. I apologize if I misuse any terms, because I learned them all in the past few days.

I purchased all my parts (everything) from a local store. The salesman installed the CPU and CPU fan for me when he gave me the motherboard (an ASUS P8Z77-V - image at http://i.pcworld.fr/1228499-p8z77vdlx-haut.jpg ).

It took quite a while and I watched a lot of videos but was able to get it up and running. I installed Windows 7 64-bit, got my video card working with some test games, and was 2 hours in to transferring music/apps over when I was installing a mouse driver (for a Cyborg R.A.T 7 mouse) when my mouse and keyboard stopped responding. I figured it may have to do with the installation of those USB mouse drivers and waited patiently for a few minutes. 10 minutes later and I knew something was up. I restarted my PC. It then never started again. I opened it up and found that it would just infinitely loop between the CPU_LED and DRAM_LED lights, back and forth.

I have tried resetting CMOS, leaving it over night un-powered, tried setting both ram sticks in and out in different configurations, and unplugging everything but the power. There's a giant CPU cooler on it ("Cooler Master"). To see if the case or cooler was causing a short, I removed the motherboard from the case, removed the CPU cooler and everything BUT the power, and powered everything on - still I get the flashing lights back and forth. I didn't try this too long after removing the cooler because I don't know a lot about these things and didn't want to risk it overheating after 10 seconds. The fans and everything work fine if they're plugged in, so I don't think it's the PSU (a Corsair HX650W).

Because of everything I've removed, this problem is somehow being caused by:
-The motherboard itself
-The CPU
-The 4 and 24 pin power adapters

I would think everything points to faulty hardware - but the problem is that everything worked fine for a few hours, and powering down and then up again (which I had done many times before) caused something to stop working. This happened as I was installing a mouse driver/software. Could this have any effect on the hardware or is this just a coincidence?

I recorded what the lights look like when I try to boot: http://youtu.be/w_qEBh2HfU0 (note: this before I removed it from the case and stripped everything but the power cables - but nothing has changed since then. Imagine this happening sitting on a table with just two power cables and a single stick of RAM plugged in).

If anyone has any suggestions I would love to hear them - this is my first time dealing with the inside of a PC and it's driving me insane. I had lots of problems before this and coworkers provided me with suggestions that got me up and running. I'm on my xmas break so I don't have those resources anymore though.

Any help appreciated

Thanks!

EDIT: If anyone has similar symptoms... check that your case's "reset" button is stuck in the down position. Obviously this just causes the first few startup checks to loop infinitely..... :pt1cable: 


SOLVED
a b à CPUs
a b V Motherboard
December 27, 2012 6:39:40 PM

Did you make sure to put your standoffs in the case? Also, taking it out of the case and trying it is known as breadboarding, your CPU likely will not boot if no fan is plugged into the CPU_FAN header, make sure that is plugged in when your breadboarding (really, when bread-boarding you are supposed to install your CPU cooler as it should start up, I bread-boarded with my RAM, GPU, and heatsink/CPU Fan installed.
December 27, 2012 6:42:31 PM

chugot9218 said:
Did you make sure to put your standoffs in the case? Also, taking it out of the case and trying it is known as breadboarding, your CPU likely will not boot if no fan is plugged into the CPU_FAN header, make sure that is plugged in when your breadboarding (really, when bread-boarding you are supposed to install your CPU cooler as it should start up, I bread-boarded with my RAM, GPU, and heatsink/CPU Fan installed.


Oh OK - I will plug the fan back in right now. I removed just to try remove another variable from the equation but it didn't seem to solve anything.

Also I removed my video card, as the on-board one was enough to install Windows and such.
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a b à CPUs
a b V Motherboard
December 27, 2012 6:44:17 PM

What if you try to boot with no ram at all? Does it do the same thing or does it just beep like mad indicating the board knows it has no ram. If it does the same thing I would guess the issue is the PSU. If it beeps like mad then the issue is with the board CPU or ram.

My guess is the 5volt rail in the PSU is defective and died. It is very common for PSUs to fail after only a few minutes.

I would ask the guy at the store to test it or see if he has a loaner you can try. Or you can get a PSU tester for like 15$.
December 27, 2012 6:49:34 PM

bucknutty said:
What if you try to boot with no ram at all? Does it do the same thing or does it just beep like mad indicating the board knows it has no ram. If it does the same thing I would guess the issue is the PSU. If it beeps like mad then the issue is with the board CPU or ram.

My guess is the 5volt rail in the PSU is defective and died. It is very common for PSUs to fail after only a few minutes.

I would ask the guy at the store to test it or see if he has a loaner you can try. Or you can get a PSU tester for like 15$.



Sorry for the video being so long - near the end I remove the RAM and still no change (and no sounds from speaker). The only difference, and maybe I'm just seeing things, is that it looks like the RAM light stays lit a little longer and they toggle back and forth.

So this probably indicates a problem with the PSU?

It's quite a travel back to the store I got this from (I would have to cab it) - are there any quick/cheap/hacky ways to verify that the PSU is faulty? Otherwise I guess I'll have to head back and get them verify this.

Thanks!
a b à CPUs
a b V Motherboard
December 27, 2012 6:57:56 PM

well you can jump the psu with a paperclip but that will only tell you if it will power on, not if the 5 volt rail is working, or if the PSU can handle any load.

Look up on youtube, jumping psu or starting psu with jumper.
December 28, 2012 3:55:41 PM

Hi,

I ran a got another PSU to swap out and test with. I got the exact same pattern of blinking LEDs and no POST.
Am I safe to assume something mucked up with the motherboard or CPU? If so, I did purchase a warranty for all parts and would be able to take it back to the shop where they promised they can troubleshoot and call me back with it fixed in 3-5 business days.
a b à CPUs
a b V Motherboard
December 28, 2012 8:45:33 PM

you seem to have tried everything. The memory controller, pcie controller and pretty much every thing else is on the CPU. Last thing you can try is to remove the CPU inspect the socket for any bent or stuck pins and then reinstall the CPU. Keep in mind you will need fresh thermal compound.
!