1. TechSpot is dedicated to computer enthusiasts and power users. Ask a question and give support. Join the community here.
    TechSpot is dedicated to computer enthusiasts and power users.
    Ask a question and give support.
    Join the community here, it only takes a minute.
    Dismiss Notice

PC Shuts off after 3 seconds

By Spazzmatic ยท 14 replies
Oct 11, 2006
  1. The other day I went to boot up my PC and it turned on for about 3 seconds or less (the fans lit up and turned), and then it died. At that point there was a green light on the on/off switch that remained steady green.

    It doesnt appear that the machine even got to CMOIS or the hard drives spinning up... power pressed, 1-3 seconds on, then dead. I kept turning it on and off, and tried different outlets too.

    EVENTUALLY... it DID power up, and has been running fine since, on multiple shut downs and reboots.

    I am wondering if this is possibly power supply related?
    I just ordered a PS tester.

    Any idea what could cause this?
    A switch stuck? Insufficent power? Dust? Failing PSU? Shorted wire?

    Is it possible to isolate this issue? Since the PSU tester will for sure so its fine now.

    The pc is used on different sites for business purposes, and if it crashes it will be devastating!!

    any help would be greatly appreciated.

    ASROCK Motherboard
    2.8 ghz AMD Athlon XP CPU
    512MB RAM / 2 HD's
  2. lordesf

    lordesf TS Rookie Posts: 19

    yes your problem happened to me 2 days ago when my comp started up for 1 sec and dead, the motherboard LED light were on except wont tart up, i got my computer fixed when i found it it was the PSu tht broke, i chnaged a new one and sweet now :)

    So change your PSU
  3. AtK SpAdE

    AtK SpAdE TechSpot Chancellor Posts: 1,495

    It could almost be any of those.

    A few other things that come to mind,

    Bad mobo sensor, reading a high temp, and cutting itself off. YOu may want to check your temps.

    A little more about a shorted wire.

    I once had a machine that kept randomly cutting out. I unplugged everything but the P1 (main) power connector and took the RAM out. I put each stick in one by one, than each component back in, eventually found it was a bad fan.

    Basically, the best way to handle the situation is by the process of elimination.
  4. Spazzmatic

    Spazzmatic TS Rookie Topic Starter


    great, glad u got it fixed. what PSU did you go with? I've struggled to determine which ones are better, as some are made pretty cheap.

    AtK SpAdE,

    process of elimination? is it possible that a bad fan would cause this to happen? I have 3 fans installed on the system. There are temp sensors in the HD enclosures, but it never got those booted up.

    Funny thing... after multiple attempts to boot, and just about giving up, it IS working now, as I had it running last night for hours. If the PSU was bad, wouldnt it be dead PERIOD? or is there any possibility of intermittent failure?
  5. lordesf

    lordesf TS Rookie Posts: 19

    im not sure :S, thats strange my PSU is kiinda a cheap one $40 its some low noise fan, but the guy told me it was better than my past one that broke so yeh..
  6. AtK SpAdE

    AtK SpAdE TechSpot Chancellor Posts: 1,495

    There is a good chance that if your PSU is going to die, it will do so slowly. Also, if a fan is shorting out a system, normally it is pretty consistant. (rig will not boot)

    Can you check CPU temps in BIOS?

    It is looking like a PSU problem, but you should check out all avenues before dropping the cash for a new PSU.
  7. Spazzmatic

    Spazzmatic TS Rookie Topic Starter

    during the one occurance there wasnt enough time to get to CMOIS, it wouldnt stay on that long.

    The PC has been powered up only once a week for the last 2 years.
    Usually all is good. But as I recall there was a similar "no power up" problem at least one time before (about 6 months ago) and I attributed it to bad electrical current. Found a new outlet and it worked.

    Still exploring this "fan" concept,... didnt know that a bad fan would cause a no boot situation...hmmmm...
  8. streblo

    streblo TS Rookie

    I had those problems twice:

    1) Bad PW (the one that came with the case). Got a decent one and problem solved (no more than $40)

    2) a cheap mobo had caps burned. just got an asus.
  9. Spazzmatic

    Spazzmatic TS Rookie Topic Starter

    PW? I assume you mean power supply?
    what qualifies as a "good one", I'm still debating what kind to get
  10. streblo

    streblo TS Rookie

    yes, I meant PSU. For me, any brand name psu will be right. Avoid generics and super-cheap ones.
    There is no point in spending months researching the market and buying a $200 PSU unless you have an exceptionally highly demanding system. I'd say brands like enermax, fortron/sparkle, ultra, etc.

    Mine is a Fortron. Costed only $20 more than a generic and works very well. Silent and reliable.

    There used to be a list of good and bad brands in one of the techspot forums, maybe somebody has it handy.
  11. N3051M

    N3051M TS Evangelist Posts: 2,115

    Just to answer the question about a bad fan stopping the PC from booting- If the main fan for the CPU fails (stopped spinning) then the PC automaticaly switches off as a protection mechanism so your PC doesn't catch on fire (worst case scenario) or damage any critical components due to overheating (namely the CPU)

    If you are going to replace the PSU, first check how much your PC needs in terms of power. You can use this PSU Calculator to help you find out your absolute minimum needs, then add 50W or more as headroom. Don't forget to press "calculate" again after changing a value.

    Few good brands to add to streblo's list are Coolermaster, Seasonic, Antec among others.
  12. Jvdhoeven

    Jvdhoeven TS Rookie

    Had the same start-up problems as described above. First changed PSU which seemed to work but problems returned. Then decided to boldly go where I never went before and check the caps. And indeed, two 3300microF10V caps had brown stuff coming out. Bought new ones for almost nothing, melted them in and surprise, surprise, all problems gone.
    Thanks for all the suggestions above!!
    BTW: AOpen AK73 Pro(A) motherboard, AMD athlon 1GHz, 5 years old system which has now 2 HDD, 2 DVD, all PCI slots filled.
  13. streblo

    streblo TS Rookie

    Congrats! Great you dared to solder the caps. I replaced the MOBO instead... :(
  14. wilson1

    wilson1 TS Rookie

    I have the same problem with my 2 day old system i just finished building, it starts for a few seconds, the fans, heatsink fan etc. all start bbut after a second they all stop again and then i cannot start it up again for some time.. and when i do the same thing happens, also there are no beeps when it turns on. and does it make a difference which way round u plug ur Power SW wire?
    Or couldit be a fried motherboard? i dont think its the PSU its brand new like the rest of the system.
  15. N3051M

    N3051M TS Evangelist Posts: 2,115

Topic Status:
Not open for further replies.

Similar Topics

Add New Comment

You need to be a member to leave a comment. Join thousands of tech enthusiasts and participate.
TechSpot Account You may also...