1. Computer problem? Tech Support Guy is completely free -- paid for by advertisers and donations. Click here to join today! If you're new to Tech Support Guy, we highly recommend that you visit our Guide for New Members.

PC Constantly Power Cycles

Discussion in 'Hardware' started by TheKid7, Oct 10, 2008.

Thread Status:
Not open for further replies.
Advertisement
  1. TheKid7

    TheKid7 Thread Starter

    Joined:
    Mar 31, 2007
    Messages:
    10
    I have been having problems with one of my PC's over the past several months.

    Problems:

    1. Over the past several months the signal to the monitor would be briefly lost ever few seconds on occasion but not always.

    2. The other day when I turned on PC it booted up OK but there was no sound. I looked in the Device Manager and there was no mention of the Sound Blaster sound card and there was no volume in the system tray. I booted into the BIOS to make sure that the onboard sound was still showing disabled and it was.

    Upon reboot the PC would not boot. There was no signal to the monitor and no hard drive activity. I tried a few more times but the Reset button did not seem to work. I then tried several times to boot a Seagate SeaTools Boot CD. After several Resets I was able to get to SeaTools but the mouse would not work and the PC seemed to be locked up. I tried a few more times with the same results. In desperation I decided to remove the CD and try to boot to Windows and it worked and the Sound Blaster card was showing up now and I have sound. I tried a couple of more reboots and everything seems to be normal.

    3. Today, my PC has really started acting up. I powered up the PC and started the Login process and the PC began restarting every few seconds as if it were power cycling. I turned it off with the Power Supply switch and went through the longer than normal task of switching out the power supply (There is a cross-bar which blocks the power supply so that you have to remove the motherboard to change out the power supply.).

    Upon startup with the new power supply the PC immediately began restarting every few seconds in the same manner as with the other power supply.

    Questions:

    1. Could it be the case power-on switch? If so, is it feasible to change it out. (It is an Antec case).

    2. Would a bad motherboard cause symptoms like this? How would I determine this since I have no spare motherboard?

    3. What other things could be causing this problem?

    4. What would you suggest for the next step(s) in diagnosing the problem?

    Thank you.
     
  2. frankjohn

    frankjohn

    Joined:
    Nov 20, 2005
    Messages:
    2,798
    restarts are usually caused by bad memory or heat
     
  3. win2kpro

    win2kpro

    Joined:
    Jul 19, 2005
    Messages:
    11,670
    Disconnect both the kk connectors for both the power on switch pins and the reset switch pins from the front panel motherboard header.

    Momentarily "short" the power on pins at the motherboard front panel connector. Leave the machine running for a little while, and see if the machine resets itself. If the machine resets itself with the reset and power on connector disconnected, the problem is in the board circuitry.

    If the machine starts and does not reset itself with the power on and reset switches disconnected, power down the machine, and reconnect the reset switch. Restart the machine by again momentarily "shorting" the power on switch pins with the reset switch connected. If the machine starts resetting itself with the power on switch disconnected, and the reset switch connected, the problem is a defective reset switch.
     
  4. TheKid7

    TheKid7 Thread Starter

    Joined:
    Mar 31, 2007
    Messages:
    10
    Thank you very much for your help.

    I followed all of your steps. However, the problem seemed to have gone away on its own. It did not show up on the test steps. I did not see anything obvious about the reset and power on connections. I tested the reset switch and it worked fine.

    While I was typing the above, I looked over and Windows had started a normal shutdown on its own. After the shutdown, I started the PC again and quickly went into the BIOS to see if the CPU was overheating. The CPU temperature was reasonable and steady. Then after about a minute the PC started doing the quick power on and power off cycles again (Every few seconds).

    Does anyone have any more ideas?

    I am thinking about just getting a new system. This one is almost 4 years old. However, I would like to see if I can fix this one first.

    Thank you.
     
  5. frankjohn

    frankjohn

    Joined:
    Nov 20, 2005
    Messages:
    2,798
    Memory or heat, Since the PC cant stay on for a period of time i was going to say do a memtest
     
  6. win2kpro

    win2kpro

    Joined:
    Jul 19, 2005
    Messages:
    11,670
    f you have another power supply you can use with the unit, try it. There may be a problem with the PS ON or PWR GOOD lead on the power supply.

    If the power supply is not the problem, then it is most likely there is a defect in the board circuitry.
     
  7. Sponsor

As Seen On
As Seen On...

Welcome to Tech Support Guy!

Are you looking for the solution to your computer problem? Join our site today to ask your question. This site is completely free -- paid for by advertisers and donations.

If you're not already familiar with forums, watch our Welcome Guide to get started.

Join over 733,556 other people just like you!

Loading...
Thread Status:
Not open for further replies.

Short URL to this thread: https://techguy.org/758005

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice