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Computer is not turning on at all

By mageknight12
Nov 8, 2007
  1. My grandfather handed down to me a mother board and some other parts to a computer he couldnt get to turn on, the motherboard is brand new and its only about a year old.

    i used the mother board with some parts from my custom built computer but it doesnt look like the computer will turn on. Nor does it show any signs of power. i tried replacing the power cord and eventually i tested the motherboard with another power supply. the one i use has a power switch on the back, but the one tested with has a green LED to show when the power supply is getting power. It was glowing green so its getting power, just not to the mother board.

    Is there any other trouble shooting i can do? i really dont want to replace the mother board or test another mother board.:dead:
     
  2. Rik

    Rik Banned Posts: 3,814

    Tried looking in our Guides and solved issues forum?
     
  3. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    Closer!

    okay well that actually helped some, i didnt have anything protecting the screws holding the motherboard in, so it was grounding?

    anyway now it turns on for less than a second and shuts off.

    theres a red light and green light, the the green one means its turned on obviously, but the red one must be sleeping or something, but thats the one that turns on. any ideas?
     
  4. Rik

    Rik Banned Posts: 3,814

    It would help if you said what mobo you have.

    The green led is usually to show that the mobo is getting +5v standby, nothing more.
     
  5. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    er hm i can try to figure out let me look.

    but also the fans start to run too with the led in the fan like its trying to start.

    lemme see if i can figure out what mother board it is.

    any specific place on the motherboard i should find it?

    gah i havnt really touched the tower but now its not turning on at all again... darnit
     
  6. Rik

    Rik Banned Posts: 3,814

    Do you have a spare psu to try it with?
     
  7. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    well i got it back to running for half a second, but yeah, i have spare motherboards, graphics cards, various pci cards. and ive tried another psu before but that was before i got it to run period. let me see what that does.

    however just an FYI the spare PSU i have is a HP and its smaller and probably not as powerful but ill give it a go

    yeah the spare psu had a light glowing showing that its getting power, but its not giving the motherboard power i dont think
     
  8. Rik

    Rik Banned Posts: 3,814

    Do you have a decent psu that you could perhaps borrow for test purposes?
     
  9. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    lemme see what i can find. i mean that other psu wasnt that old, its just meant for a small computer. ill reply with an update soon
     
  10. Rik

    Rik Banned Posts: 3,814

    I figured that that psu may well not be powerful enough to test with.
     
  11. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    now ive used the psu from the computer im on right now. when i plugged it in the LED flashed a second like it got alot of power, nothings shot but for some reason or another it wouldnt turn on.

    maybe i did something wrong but i really only need to put the pins in from the psu to the motherboard correct?
     
  12. Rik

    Rik Banned Posts: 3,814

    Is the pc you are trying to get working a new build or has it been working ok in the past?
     
  13. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    the mother board that im trying to use is basically brand new. i have a custom computer that started to go faulty and i was given all these spare parts so i replaced my motherboard and put in some new hard drives and cd roms. but the PSU is the one from my old computer and it ran previously. so its not broken.

    everything is plugged in correctly i believe,

    what could make it only run for less than a second?
     
  14. Rik

    Rik Banned Posts: 3,814

    It could be any number of things really. Do you get any beeps of any kind when it does work for that short time? (bit of a long shot)
     
  15. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    nah, it just powers up and powers down, not enough time for the fans to spin atleast more than 5 times around

    i DID have beeps prior to replacing the mother board, but i found out it was because i had my hard drives set up wrong. (dont think that means anything now) but,


    the POWER LED connection doesnt fit, its three holes but theres only 2 pins on the motherboard set for the LED, that probably has nothing to do with it considering is just the light, not the switch itself..

    hm.
     
  16. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    okay, so eventually the smaller psu unit DID get my computer to run! i messed with the power switch cables attatched to the switch itself, wether that was the problem or not i can not say. but it was full running, but being the ***** i am, i decided that having a PSU just lying ontop of the computer wasnt safe, and that i should atleast plus in a video card to use the moniter properly. well once i screwed in the psu now im not getting power anymore.... and its not like i did anything specific that made the computer work.


    well then i had previously tried various psus on the motherboard so when i tried to attach my psu back the the computer ive been using, that too failed to work. now ive got two broken computers. this one looks like the hard drive and cd roms arnt getting power but the fan is.......

    great.... i need so much help lol
     
  17. Rik

    Rik Banned Posts: 3,814

    I wonder if the power switch is dodgy. Try carefully shorting the 2 pins on the mobo momentarily with something metallic like a screwdriver and see if it will start up like that.
     
  18. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    its not the power switch itself, just found that out. i think its the motherboard 20pin input. maybe it has a short.

    well like i said i got it running last night but like an ***** i turned it off.

    today i took everything out of the broken computer 1 and put it in my newly broken computer 2 lol

    this time i just started messing with the 20pin from the psu, i used a 20 to 24 pin adapter a bought, to save me from pulling the 12v 4 pin out all the time aswell. so basically im messing with this 24pin when all the sudden half of the pin is in and the cd roms and HD start picking up power and start working but not the fan, so i push the 24pin in the rest of the way and the fans start running. the power switch wasnt plugged in so i couldnt turn it off with the switch.

    but honestly i dont think the PSW cords are plugged in right, on this box the PSW cords are all in one, rather than split into LEDs and Switches.

    but anyhow im thinking there is a short in the motherboard or something....any ideas?
     
  19. Rik

    Rik Banned Posts: 3,814

    So, you arent connecting the 4pin 12v? If thats the case, thats probably why it wont work.
     
  20. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    well im using a 20 to 24 pin adapter instead, but i mean ive tried it the otherway aswell, and im not getting results at all with the 4pin. the network lights are on, so the board gets power scince the they are on. but the fans nor the HD and CDROMs are getting power.

    if i remember right, the 4pin and 20pin give it the same results, but with the 24pin adapter it seems to try to turn on and go off quickly.
     
  21. Tedster

    Tedster Techspot old timer..... Posts: 6,000   +15

  22. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    well it wont even turn on so no beeps or sounds will go off. im assuming its a no post problem. well i guess ill try every step but i think in the end im going to have to buy a new motherboard. sigh*
     
  23. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    well great news, ive got my computer back up that i broke in the fixing process of the other computer hah.

    okay so im back where i was. ive got a computer that possibly has a short in the 20 pin input on the mobo, is that possible? or improbable? im going to go through the entire post guidlines but i dont think itll help. wish me luck
     
  24. Tedster

    Tedster Techspot old timer..... Posts: 6,000   +15

    shorts are always a negative chance.
     
  25. mageknight12

    mageknight12 TS Rookie Topic Starter Posts: 17

    okay, well lets see what happens when i run the NOPOST guide.


    i knwo this is off topic but its the second time my moniters been running then all the sudden randomley on its own decide it wants to go to sleep and not come back on when im in the middle of something.

    i have to reboot my comp just to fix it. any explaination?
     
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