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HELP!! PC won't boot after attempted upgrade

Last response: in Components
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August 13, 2009 3:28:53 AM

Hey guys,

Hopefully someone has some experience with this scenario. My PC has been working fine for 14 months. I've been experiencing corrupt GPU memory symptoms with my GTX 260, so I purchased a GTX 275 to see if the issue would go away (intermittent green dots on the screen...and they also showed up on print screens). Anyway, after I installed the new GTX 275, the PC won't boot, the lights and fans just come on for a millisecond and then nothing. I think I might either have a bad PSU or mobo. I hope I didn't fry the mobo. I even went all nerdy and used an anti-static wrist band. It may be worth noting that I had the PSU plugged in while I did the work, but the switch in the back was off. This was an attempt to do everything by the book so that I wouldn't fry the hardware....but I'm wondering if that's what killed it. I also tried putting in the old GTX 260 again, and it does the same thing....no power.

The PSU in question is an ABS Tagan BZ-800 PSU (800 watt). I've seen some pretty awful reviews on those, so I'm thinking it might have finally failed me. Tonight I bought a Corsair TX850 PSU, but then got the horrible feeling that maybe this is a mobo issue. Does anyone have any experience with this issue? I've already tried holding the power button on the case down to "reset" the PSU, but that didn't work. Please help!

Thanks,

Paul

More about : boot attempted upgrade

a b ) Power supply
August 13, 2009 2:35:21 PM

"the lights and fans just come on for a millisecond and then nothing" - sounds to me like one of three possibilities.

1. You're right - the PSU has suddenly failed (maybe the new video card pulls more power? - and needs to be replaced. You have a new PSU to install, but try the next ideas first.

2. Somehow in doing the card replacement you disturbed something that created a short circuit, overloading the PSU, or a poor connection that fails to supply power where needed. The very fast shut-down suggests overloaded PSU (a short somewhere?), rather than a component without power. Look around for loose connections. Look for loose pieces in the wrong place - did you drop a screw that is stuck somewhere? Check that the power connections to your new video card are done right, if there are any. Check that the new card really is inserted correctly in its PCI socket.

3. A quick shut-down (typically a few seconds of operation first) can be the result of very poor cooling of the CPU. If the CPU cooling fan does not run from the very beginning, or if somehow you loosened the heatsink from the CPU, the CPU will overheat very quickly and shut down the entire system to protect itself. Check the heatsink mounting to be sure it is secure.
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August 13, 2009 6:26:05 PM

Paperdoc said:
"the lights and fans just come on for a millisecond and then nothing" - sounds to me like one of three possibilities.

1. You're right - the PSU has suddenly failed (maybe the new video card pulls more power? - and needs to be replaced. You have a new PSU to install, but try the next ideas first.

2. Somehow in doing the card replacement you disturbed something that created a short circuit, overloading the PSU, or a poor connection that fails to supply power where needed. The very fast shut-down suggests overloaded PSU (a short somewhere?), rather than a component without power. Look around for loose connections. Look for loose pieces in the wrong place - did you drop a screw that is stuck somewhere? Check that the power connections to your new video card are done right, if there are any. Check that the new card really is inserted correctly in its PCI socket.

3. A quick shut-down (typically a few seconds of operation first) can be the result of very poor cooling of the CPU. If the CPU cooling fan does not run from the very beginning, or if somehow you loosened the heatsink from the CPU, the CPU will overheat very quickly and shut down the entire system to protect itself. Check the heatsink mounting to be sure it is secure.


Thanks for the reply. I was beginning to wonder if I knocked something loose that was causing a short, but just for kicks this morning I tried it again, and it works! I didn't do anything to "fix" it. In a half asleep state this morning I thought I heard the PC "release" something, like stored power or energy (almost like a loud pop, but I wasn't fully awake). Anyway, sure enough, it's running like a champ as I type. I wonder if it went into some kind of mode....maybe because of the way I had it plugged in but switched to off. I'm just glad it's working. Thanks again for the suggestions though, I appreciate it.

-Paul
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August 14, 2009 3:53:59 AM

Bump.

Sorry, don't mean to be a pest or anything, but I was just wondering if someone had an idea as to why my PSU went into this state of not functioning for, what seems like, an even 24 hour window. It stopped powering up after I put the new GPU in, but when I woke up this morning it powers up just fine (and I changed nothing after the GPU upgrade to "fix" it). Is this a "feature" in some PSUs?? Or is it failing on me? Don't get me wrong, I'm stoked that it's working, but I'm more than a little confused about what the heck I did wrong.

Thanks,

Paul
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a b ) Power supply
August 14, 2009 1:45:27 PM

I really don't have an answer here. The machine simply would not turn on. Then while turned off, in the early morning it "pops" and, later, you push the front button and it comes on just fine. Computer fairy godmother? Lots of real possibilities, but many almost as fanciful as fairies.
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a c 144 ) Power supply
August 14, 2009 5:56:17 PM

Many PSU's, when they seemingly lockup and die, need to be physically turned off by either the PSU power switch or unplugging the power supply. I have not seen schematics for any modern PSU's (something about "proprietary", no doubt), but older schematics show several different ways of generating the "PowerOK" signal that the motherboard needs to boot.

On some that I have seen, the "PowerOK" circuitry is powered by the standby power supply. That's always on. But if it locks up, I can see needing to pull the plug to reset it.
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August 14, 2009 6:08:53 PM

Paperdoc said:
I really don't have an answer here. The machine simply would not turn on. Then while turned off, in the early morning it "pops" and, later, you push the front button and it comes on just fine. Computer fairy godmother? Lots of real possibilities, but many almost as fanciful as fairies.



Haha, I was beginning to think the same thing. It's definitely strange. After doing some research, I finally seen it explained as "trapped electricity". Apparently, sometimes electricity can become trapped under a capacitor or other component (and can happen pretty much anywhere on a PC). The suggested remedy is to completely disassemble the PC, unplugging every component, and let everything sit for at least 24 hours so that all electricty can "bleed" out. In my situation, I think I lucked out and the electricity was trapped in the PSU, because I didn't have to disassemble anything. The fact that the PC was powered off for 24 + hours must have given it time to purge the electricity. The sound I heard may have been the phenomenon taking place, or it may just have been me passing gas in my sleep.

The reason this whole thing happened is my fault, I believe. You see, I tried to follow everything by the book, but before I plugged the PSU in and turned it off, I didn't bleed the power from the computer by holding down the power button on the case. I've since read that this should be done to prevent electricity from becoming trapped under components. Oh well, live and learn.

Thanks for taking the time to read and answer my questions, Paperdoc.

-Paul
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