Problem: PC powers up and then shuts down???

H

homerjelly

Weaksauce
Joined
Apr 20, 2006
Messages
92
I have a really strange problem and I'm just stuck. I'll summarize to make this an easier read.

MAIN ISSUE: It turns on. The DVD spins up and fans spin up and then after 3-5 seconds, it shuts down and restarts itself. Nothing shows on the LCD. No boot message. No POST beep.

A Few Months Ago:
- Changed the video card on my wife's PC.
- PC starts having the problem above and constantly keeps rebooting itself.
- I tested different RAM, different PSU, the old Video card and unplugged peripherals. Still the same problem.
- I fiddled around with connectors/wires and somehow it starts up.
- Since then it works fine but sometimes it just restarts itself late at night (and ONLY late at night).

A Month or So Ago
- PC still strangely reboots itself on random nights
- Every 3-4 days a really weird error comes up and the PC crashes. Sorry I don't have the error message.
- I thought it was the motherboard.
- Changed the Motherboard
- PC is working fine. Yay!

Present Day :)
- Some construction in the basement got a lot of dust in the PC.
- So I turn off the PC to dust inside.
- PC is no longer turning on. Back to the Main Issue again. Exactly the same.
- I've decide there is a short in the case and I need to change it.
- PC is now in a new case. IT'S STILL NOT WORKING :( :(

=> BACK TO THE BEGINNING: SAME PROBLEM as the Main Issue above!! :mad: :mad:

PC is just not booting up anymore (but it turns on) and I'm ready to shoot it!
Any suggestions/help appreciated! I'm at the end of my troubleshooting skills with this.
 
Is your house giving it a consistent and safe flow of electricity? Computers can be very sensitive to that kind of thing - not just surges or blackouts, but also "brown outs" and "dropouts". Inconsistent electrical supplies can cause component overheating or failure. Surges, of course could fry your gear.

Some people with inconsistent power in their homes test and repair the home electrical system, and others buy a UPS (Uninterrupted Power Supply), which gives relatively consistent energy and also gives you the added benefit of time to save/shut down in case of an outage.

I'm not sure if that's the problem or not, but it's worth investigating.
 
Strip it down to the barebones, just one stick of RAM, processor, etc. See you if that will get you a POST beep, try running it outside of the case on just an anti-static bag as well. Try rotating sticks of RAM, etc. as well, make sure all your power connections are firm and all the normal stuff. Report back after you've done all this.
 
swingdjted said:
Is your house giving it a consistent and safe flow of electricity? Computers can be very sensitive to that kind of thing - not just surges or blackouts, but also "brown outs" and "dropouts". Inconsistent electrical supplies can cause component overheating or failure. Surges, of course could fry your gear.

Some people with inconsistent power in their homes test and repair the home electrical system, and others buy a UPS (Uninterrupted Power Supply), which gives relatively consistent energy and also gives you the added benefit of time to save/shut down in case of an outage.

I'm not sure if that's the problem or not, but it's worth investigating.
Click to expand...

Thanks but I don't think it is the home wiring as my other computer is just fine and it uses alot more juice.

kmS said:
Strip it down to the barebones, just one stick of RAM, processor, etc. See you if that will get you a POST beep, try running it outside of the case on just an anti-static bag as well. Try rotating sticks of RAM, etc. as well, make sure all your power connections are firm and all the normal stuff. Report back after you've done all this.
Click to expand...

Aye aye cap'n! ;) Was planning that anyway, just wanted any other suggestions.
 
I think you should be careful not to make the fallacy of assuming that because you're seeing the same symptoms, the cause must also be the same.

Lots of things can lead to a pre-POST looping computer. A failing PSU can do it, bad BIOS settings/failed BIOS flashing can do it, motherboard incompatibilities can cause it, and anything that messes with current enough to "scare" the system can do it as well--in other words, any failing component could theoretically cause this. I'd say follow kmS's advice, it's probably the only way to get sanity for now. Just remember that you could easily have more than one problem, or one problem that caused another, or an intermittent problem that might not be readily apparent. Hope you get to the bottom of it.
 
HydroBudz said:
Flakey PSU? Have you tried replacing that?
Click to expand...

Danny Bui said:
What PSU is in that system? What other PSU model did you try with that system?

But so far the kmS's advice is the one you really need to try
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It has a 700 Watt OCZ PSU. The first time it happened, I tried my other OCZ 900W ModXstream and I got the same problem.

Yeah I'll be trying to strip it down and do the usual tonight or tomorrow morning.

Code: 
Specs:
700 Watt OCZ PSU
Intel Core 2 (around 2.33 Ghz?) - can't remember atm.
OCZ PC2 8500 DDR2 RAM - 2 GB
ATI 4850 Video card
2 Hard Drives
1 Burner
Nothing Overclocked.
 
Well here's the verdict:

1) I feel like such a newb.

2) It was the RAM.

Strangely enough the RAM works fine in my other computer but not in this one.

Just one question is bugging me. Why is it the RAM had problems months ago then it suddenly works fine for about 3 months then it starts up again???

Thanks all!
 
Sun spots.

No really, could be anything. I've had vid cards get all hokey on me for a day or two, then magically it works fine for months, then it starts again. Could be a bad trace on the PCB, flakey transistor, not-so-clean power. One of lifes mysteries that may never be answered.
 
Have you tried anything like rubbing the contacts with a pencil eraser? Also, the RAM could just be difficult to seat properly--it might look/feel like it's in, but every slot will have different tolerances and what have you despite standardized sizes. Could be the stick or the slot style. I know I've seen motherboards with really tight or really loose slot retention before, ones that had me worried I was bending the motherboard just by slotting the memory. Of course it could just be flaky RAM, certainly wouldn't be the first time.
 
HydroBudz said:
Sun spots.

No really, could be anything. I've had vid cards get all hokey on me for a day or two, then magically it works fine for months, then it starts again. Could be a bad trace on the PCB, flakey transistor, not-so-clean power. One of lifes mysteries that may never be answered.
Click to expand...

+1

Phyltre said:
Have you tried anything like rubbing the contacts with a pencil eraser? Also, the RAM could just be difficult to seat properly--it might look/feel like it's in, but every slot will have different tolerances and what have you despite standardized sizes. Could be the stick or the slot style. I know I've seen motherboards with really tight or really loose slot retention before, ones that had me worried I was bending the motherboard just by slotting the memory. Of course it could just be flaky RAM, certainly wouldn't be the first time.
Click to expand...

Meh I'm not gonna bother. I tested it a few times by putting the OCZ RAM in different slots with either stick and it always failed.

Then I tried the GSkill and it always worked.

So either way I got the extra GSkill lying around and I'll get rid of the OCZ (warranty it then resell).
 
I'm having the exact same issue. I was just about to post this:


Antec 550w power supply
Asus P5Q Pro
LGA775 E8400
ATI 2600XT

I installed everything in the case. The computer ran fine for 3 days straight. Installed windows, all software etc. Multiple reboots and no problem.

After everything was working fine, I shut down the computer in preperation for wire management and clean up.

After I powered it down I forgot to do one thing, so I go to power it up and only the CPU fan, and my exhaust fan, as well as the fan on the Power supply spin for like 3 seconds. It then stops running and tries to boot itself again.

I powered down via the power button for 4 seconds, hit the power again and no problem.

So eager to get it going I spend tons of the time making the wiring look good, go to boot it up. Same issue again. Powers up for 3 seconds, powers down, tries to power up again etc etc

With the fans turning on, is that a sign that the power supply still works? Or could it be the issue? I'm going to buy a new one after work to see if that is indeed the case. I know 100% all my system connections are fine.

I even unplugged everything. just the CPU and the CPU fan is connected, everything else taken out and still same issue.

I don't think the motherboard fried, I mean it booted up before after I was having this issue so maybe even though the power supply is new, it might be dead.

Any suggestions or advice if the power supply works or may be dead?

Thanks in advance to any responses.
 
Sorry to post at the end of your thread homer,

Just an update on my issue. I have taken the computer out of the case, and running it on a cardboard box. Powers up no problem. So obviously it's shorting out somewhere on the case.
 
Franjo said:
Sorry to post at the end of your thread homer,

Just an update on my issue. I have taken the computer out of the case, and running it on a cardboard box. Powers up no problem. So obviously it's shorting out somewhere on the case.
Click to expand...

Then look for any loose screw, cable, wire, standoff or anything that shouldn't be there.
 
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