Computer dead, then runs, now dead again.

[bullwinkle8]

This has me going in circles.

I built a new PC.  It runs fine, boots up and I load XP.  I put it aside for 1 month.  When I start it up again, it burps and then goes dead (although there is a green light which is on on the mb, so I know power is going there).

So I begin to dismantle it.  I take out everything and isolate the mb on newspaper.  It runs.  I then put back each piece of hardware, testing it each time until the entire system is rebuilt.  It runs every time.

I'm happy.

And THEN I see this OCZ 700W PSU that I fall in love with.  4 12v rails at 18amps each, I GOTTA HAVE IT!

I replace the old PSU (Enermax 660W) with the OCZ and the system dies again.  When I say "dies" what I mean is that everything runs for a split second.  Then nothing runs except for the green light on the mb.

I'm going nuts.  I don't think there is a short in the mb or PSI cards or even in the HD because it ran before.  Can anyone shed some light on this?  PLEASE?

Athlon 64 4800
ASUS A8N-SLI mb
2x nVidia 7800 video cards
2x 1G Corsair twinx 2048
320G Seagate SATA2 HD
Audigy 2 card

[ale52]

Ok, so the problem follows you even after you put in a new power supply.  So that pretty much rules out the power supply (for the moment).  

"I then put back each piece of hardware...".  What hardware are you putting back in / RAM / video / audio/ NIC?...or is all that built in the motherboard?  

"I don't think there is a short in the mb or PSI cards or even in the HD because it ran before."  That is no guarantee that it's good.  ONE of those components is defective and intermittently dying on you.  THAT is one of the hardest kind of problems to diagnose.  It's a matter of swapping out parts to get to the answer.  I know that's not what you want to hear but...welcome to the wonderful world of computer repair. :-/

Alan <><  

[bullwinkle8]

Let me state that most of this system is 2nd hand - it was running fine with a seller on ebay.  Those parts are: mb, video cards, and PSU.  I purchased the memory, CPU, CD-RW, and hard drive new.

So if I figure that the old stuff is good, then it must be something that's new that is causing the problem.  I could pull out one stick of memory, then the other.  I could put in an older HD and see if it runs after any of those changes.

OR I could take it to a PC store and pay $$$$.  Even then I wonder how much of a warranty I would receive.

What would you advise?

[Raptor]

Replace the CMOS battery.

[GX1_Man]

Let me state that most of this system is 2nd hand - [highlight]it was running fine with a seller on ebay[/highlight].  Those parts are: mb, video cards, and PSU.  I purchased the memory, CPU, CD-RW, and hard drive new.

So [highlight]if I figure that the old stuff is good, then it must be something that's new that is causing the problem[/highlight].  I could pull out one stick of memory, then the other.  I could put in an older HD and see if it runs after any of those changes.

OR I could take it to a PC store and pay $$$$.  Even then I wonder how much of a warranty I would receive.

What would you advise?

Highlighted spots are erroneous thinking. A store would warranty only what they install, and perhaps their work on that.

I would boot a Linux Live CD and see if it is functional.Was this a fresh install of Windows after the machine was assembled? The hardware could be defective and probably is IF the build was correct.  

http://www.computerhope.com/cgi-bin/yabb/YaBB.cgi?num=1152393515

[bullwinkle8]

This is my 2nd build - the first was perfect from day 1 - in fact I'm using it to write this.  So I'm not a pro, but I'm not exactly a newbie either.

When I built the PC the first time and booted it up, I was able to fully install Win XP Pro without a hitch.  That's when I turned it off and let it sit there a few weeks until my wife had a cabinet built to accommodate it.  

I will look into replacing the CMOS battery - would a defective battery cause intermittent problems like this?

I agree that it may be erroneous thinking to assume that it worked previous owner, although he told me it was fine and he gave me help in my attempt to integrate my old HD into this system.  That, plus the fact that it worked fine right off the bat leads me to thinking that the old parts are OK.

[Raptor]

I will look into replacing the CMOS battery - would a defective battery cause intermittent problems like this?

Seems like it, although when a CMOS battery is empty the system usually doesn't start at all or gives you a CMOS battery low warning...

Perhaps something else is damaged, but replacing the CMOS battery is a cheap and quick fix to rule out

[patio]

For a 3 dollar investment it i would try it first...but that's just me.

patio.  8-)

[bullwinkle8]

When we last left our Hero, he was trying to figure out why his computer kept shorting out...we now join the action:

Bullwinkle looks blankly at his dead system. Rocky offers some advice: "Replace the battery" Costing only a couple of bucks, Bullinkle does this.

The PC still shorts.

Now completely at a loss (a feeling he is comfortable with), Our Hero notices that when the system shorts there is a small spark at the bottom of the first stick of memory. "AH HA!" he thinks, I've found it! He immediately pulls out the first stick and replaces it with the second.

The PC RUNS!!!!!

Thinking that he has the problem in his hands (or hoof) he decides to test it by putting it in the 2nd memory position.

The PC RUNS?

Makes no sense to him, but few things do. He packs up the PC and takes it upstairs to hook into his monitor. He turns it on. The PC recognizes the 2 gig memory, but does not recognize the C: drive.

So Bullwinkle replaces the connection on the SATA drive with the connector that worked way back when the system posted and Windows was loaded.

The PC shorts out.

Our Hero confidently takes out the memory and reseats it.

The PC shorts out.

He puts the previous connector on the hard drive.

The PC shorts out.

Dazed, bewildered, and totally confused, Our Hero gives up and takes the PC to a PC store where he will pay Big Bucks to have this problem fixed - he hopes.

[GX1_Man]

See my reply on the 12th.