TechSpot

PC wont boot

By godrugal0
Jan 14, 2009
  1. Ok this is my first thread here. I have been building PCs for about 3 years nothing hardcore.
    My problem is as follows, I was gaming two night ago and all was well. machine got switched off at 3am and was not turned back on till 5pm the next day.
    When the power button is pressed the fans spin the mobo lights are on as are the gfx card lights but no HDD light comes on this happens for anything between 2-15 seconds then everything goes off!
    I then have to manualy switch of the PSU from the back lave for 30 seconds and switch back on, the red power light on the mobo now comes back on. As soon as I press the power button I get the same problem.
    These are the things I have checked so far

    RAM - Moved all sticks around and checked them in the first slot 1 at a time.

    PSU - replaced with a Enermax 400w (couple of years old but should be able to power my system) same problem!

    GFX - have not swapped yet as my old 7950gt is in the loft,lol

    MOBO - as above, only other one is in the loft

    CPU - not changed.

    My rig is outlined below.#
    MOBO - abit ip35-e shipped bios
    CPU - core2duo e6600 - stock settings
    PSU - Hiper type-r 580 watt
    RAM - 2x1gig crucial XMS2 matched sticks ddr2

    I had thought it was my PSU as when i connected it the fuses for the sockets had blown in my house, but now im leaning towards the mobo and this is why (kinda). When I tried the other PSU and was putting my own one back in I had connected all the cables except the 12v one that goes next to the cpu, I powered up the system and all the lights and fans came on except the hdd light, but the system stayed on it just would not boot. I noticed my error and shut it down and reconnected the 12v line, as soon as I turned it on the system shut itself off again like before. i tried this both ways a few times and it was the same with the 12v line connected it turn off immediately.

    I am now at the end of my limited skills and any help would be great. I dont want to run and get a new PSU if its the mobo or vise versa.

    Thanks.
     
  2. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

  3. godrugal0

    godrugal0 TS Rookie Topic Starter

    I reset the bios as advised to no affect the problem persists. I have noticed again that if the 12v line is connected the pc automaticaly shuts itself down i have to then turn the psu off at the back and wait for a noise (sounds like a tiny zip) after about 5-10 seconds, im then able to turn the pc on again, which will switch off straight away.
    When im waiting for the noise from the psu the lights on my keyboard and mouse flash at the same time as the noise occurs? Does this point to the psu being faulty or is the mobo fried in some way.
    If i turn the pc on without the 12v line connected everything is fine except the hdd does not come on.
    I patiently wait for the next step.
     
  4. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

    This can still be Motherboard issue, and therefore continuing the guide, in respect to Benchtesting and reseating essential components, and removing all non-essential components (including extra Ram cards) should be tried

    The PowerSupply is usually one of the first Hardware items to test by replacing - but I cannot confirm that this is your issue at this time, even with the above extra info
    It's a matter of confirming all parts to the No Post guide; then start with Hardware changeover (PowerSupply; Ram; Motherboard; CPU etc)
     
  5. godrugal0

    godrugal0 TS Rookie Topic Starter

    I will continue the post tests in the morning.
    Thanks so far.

    I dispersed the voltage and plugged back in minus the optical drive, the system powered up and ran for about 30 seconds.
    During this time the monitor flashed between analog and digital signal then switched off. after about 30 seconds the system shut down again, as above all lights off etc etc and i had to manually power down again.
    Ram has all been unseated and swapped.
    Case fan is disconnected.
    I have got my old 7950gt gfx card from the loft so will try that soon.

    I have also cleaned all the pc, using compressed air. I also did the psu which was quite dusty to say the least. the psu showed no signes of any damage when i had it open all capacitors that i could see appeared ok and the circuit boards seemed free of corrosion.

    Ok next steps taken were.

    Removed gfx card
    Removed pci sound card
    Disconnected optical drive
    Removed system blower (fan near pci slot)
    Placed one 1 gig ram stick in the dimm socket 1
    Checked mobo for any discolouration near the mounting screws, checked capacitors for bulging or leaking, checked resistors and tracks for any signs of corrosion etc. - all fine.

    Plugged power lead into the psu and then into the wall. Mobo red light came on, pressed the power switch and the fans and green mobo light came on, the hdd light also came on, system ran like this for about 20 mins.
    having thought I was getting somewhere I switched the system off to try it again and hey presto it went back to shutting itself off immediately after the power button was pressed.
    I tried this a further 3 times all with the same result, when the power button is pressed all the fans and leds come on as does the green power light and the orange hdd light for less than a second, when they go off the red mobo power light also goes off and then i need to switch the psu off wait for the zip noise and start again.
    Is this now pointing towards a mobo short??
    thanks again for any other info.

    may I also add that during the running time at no time did the HDD make any beepsing noises at all, I could here it spin a couple of times but no beeping codes.
     
  6. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

    To confirm that it's not your Harddrive, you can actually unplug it from the Motherboard end (ie not the drive end) you can also do this with the optical drive
    Then just turn on, and leave on. You will get an error that the Harddrive is not present, and therefore - no bootable device found. Just disregard this, and leave on for over 20mins. This will eliminate the Drives (all drives, including floppy drive if exists) as the issue)

    But because it's presently back to turning off straight away, you may need to disconnect the large 20 or 24 pin power connector, then hold in the ON button for 30secs, the reconnect the large power connector to the Motherboard. Which will enable your computer to then startup normally again.
     
  7. godrugal0

    godrugal0 TS Rookie Topic Starter

    Ok the optical drive is still disconnected and now the HDD is disconnected too, no warning sounds at all though! Is this strange?
    Also the yellow HDD light is still on the front of my PC? The cable connecting the mobo to the front panel led is still connected, should I take this out?
    Its running and I will leave it running for 30 mins while I have my dinner.
     
  8. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

    Hear back from you in half an hour ;)
    The front panel wires, I have found to be least likely cause (except for front USB which I have seen before in error)

    Anyway bona petite :chef:
     
  9. godrugal0

    godrugal0 TS Rookie Topic Starter

    Ok just came back from dinner, mmmmm.
    PC was off, i reset the psu and tried it again and it turned itself off after about 5 seconds with all the same symptoms as before.
    Should I now disconnect the front panel usb as well?
     
  10. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

    To avoid many replies and questions regarding what to disconnect
    Refer to the guide, and Benchtest the motherboard, or have someone do it for you

    Sorry, this thread has gone further than normal, the proceedures in the guide should be followed in full
     
  11. godrugal0

    godrugal0 TS Rookie Topic Starter

    The guide has now been followed and the problem persists.
    I will bench test the mobo tomorrow in full and report back.
    Thanks
     
  12. godrugal0

    godrugal0 TS Rookie Topic Starter

    the mobo benching test show the same results, there are no beeps to say anything is wrong or working at all. No beeps when the ram is in and the hdd out, no beeps with no gfx card (no onboard) no beeps with no ram in? no beeps when everything is connected and still the power cuts off between 2 seconds and 20 mins?

    Is the mobo done?
     
  13. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

    Yes it's hardware - proved :grinthumb

    It leans towards Motherboard :suspiciou
     
  14. godrugal0

    godrugal0 TS Rookie Topic Starter

    Thanks guys.
    When I finally figure it out I will tell you all.

    Cheers.
     
  15. godrugal0

    godrugal0 TS Rookie Topic Starter

    Well I contacted overclockers and they agreed to RMA the motherboard.
    Thanks for your help guys. :)
     
  16. kimsland

    kimsland Ex-TechSpotter Posts: 14,524

    Thanks for the update and 2nd opinion confirmed :grinthumb
     
  17. godrugal0

    godrugal0 TS Rookie Topic Starter

    Got Mobo back today and reinstalled everything as it was, and guess what? exactly the same problem, but Overclockers said the board was faulty?
    has my CPU possibly been fried by the dodgy mobo? I have an old P4 I will test with tomorrow.
    the CPU shows no signs of damage, but still there are no beeps when starting the system.
    Now im super confused. :(
     
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