powering a psu without a mobo?

rykoryko new york
edited November 2004 in Hardware
I am having a really strange problem with my 2nd pc. It is an old 1.2ghz celeron, 512mb pc1333, 20gb hdd, Antec smart blue 350w and a raidmax 289wb case.

After checking the psu rails in the BIOS...they are way too low.

+12v = 11.73, +5v = 4.89, +3.3v = 3.24

Well, i figured the psu was bad since it is over 2 years old, I took this oppurtunity to purchase a new psu for my main rig, and use my current main rig's psu to power my 2nd pc. This psu is a 450w Antec, and the rails are rock solid on my main rig and it is less than 6 months old.

So i put the 450w antec in my 2nd pc after my new ultra x-connect arrived for my main rig---which is an awesome psu btw. After installing the Antec psu, i can't even get into windows, b/c it says some file is missing or corrupted. I check the rails in the BIOS, and to my surprise/horror the readings are way too low...lower than the above readings.

So something in this build is eating known good psu's. Could something be shorting out the board and consequently the psu? Like a metal standoff or something? I am in the process of removing everything from the case, and trying it outside of the case to see if it makes a difference.

I want to be able to test my supposedly dead psu without hooking up a mobo. I know you have to "short" two pins on the 20pin connector, but which two pins? And what should i use to connect the pins? Once i figure that out, i need to take some readings with my new multimeter, but i haven't the slighest idea how to work that thing....so i will need some advice on that too. :scratch:

Thanks!

Comments

  • rykoryko new york
    edited November 2004
    Ok, I figured out how to short the 2 pins to power up the psu, but how can i measure the +12, +5, and +3.3v with my mulitmeter? I am a total noob when it comes to using this thing....and the poorly translated instructions are meanigless to me.... :wtf:
  • PirateNinjaPirateNinja Icrontian
    edited November 2004
    youre power supplies are fine! Thats actually a fairly normal read out, so dont worry about the power supplies. The reason you can not get in to windows is because there is a software problem.
  • ThraxThrax 🐌 Austin, TX Icrontian
    edited November 2004
    Your voltages are fine, however if you're still bent on testing with a multimeter:

    Black to ground, red lead to red to test 5v or 12v.
    Black to ground, red lead to yellow to test 5v or 12v.

    I can't remember which is which. Either way, you'll know.
  • rykoryko new york
    edited November 2004
    I don't think there is a software problem at all.....i thought the low voltages maybe borked my windows installation....but i just finished testing that hdd in my brother's pc (similar config--s370 celeron, etc...) and it is fine.....straight into windows.

    I also tried everything out of the case, and it makes no difference...low 12v and not booting into windows. I found a thread in here that shows how to check your 3.3v rail, and both the 350w antec and the 450w antec when not hooked up to a mobo show 3.35 steady.

    How can i check the +5v and the +12v???
  • ThraxThrax 🐌 Austin, TX Icrontian
    edited November 2004
    I just told you.
  • PirateNinjaPirateNinja Icrontian
    edited November 2004
    im really doubting its the psu causing your issues. if windows says your files are missing on one mobo, then on another it boots fine, id guess bad memory module. maybe try a docmem test?
  • rykoryko new york
    edited November 2004
    nope.....RAM is ok.....both sticks (seperately) just passed memtest+ in my brother's machine :)

    Also voltages are ok on both the 350w and the 450w....

    450w: 3.33/34, 11.89/90, 5.04

    350w: 3.34/35, 11.97, 5.09

    btw, red is +5v, yellow is +12v, and orange is +3.3v

    it has got to be the motherboard, b/c everything else is known to be good.
  • edcentricedcentric near Milwaukee, Wisconsin Icrontian
    edited November 2004
    Either memory or the drive controler on the mobo.
    boot into memtest and give it a spin.
    Do you have another machine to test the memory in?
  • pokesquid808pokesquid808 SO CAL
    edited November 2004
    take everything out except for the mobo, cpu, memory, video card, and hdd. see if it boots. if it does then one by one start adding all yoru components in. try the board in your bro's computer too. if it works then you know it's one of yoru components. or else the mobo is just shot.
  • rykoryko new york
    edited November 2004
    ok.....after spending all day and some of the evening on this, i am calling it quits.

    I have tried everything. swapped everything (cpu, video, RAM, hdd, psus) into my brother's soyo tisu board, and it all works--boots into windows fine. when i try it with my ecs p6vxat board, i can boot into BIOS, but no windows. it usually says that c:/windows/system cannot be found... also i can't do a fresh install of xp b/c something is wrong with the optical drive (ide 1) port too. it will detect the hardware in the BIOS, but the drive(any) won't detect my xp disc...or my old win2k disc. so i figured i would switch hdd to ide1 and optical drive to ide2, but then it won't detect anything on the ide ports in the BIOS and i get a hdd missing error when trying windows. i think the ide ports have gone bad...i have tried different cables too....

    i'll come back to it another day.....for now i am considering it the mobo.
  • mmonninmmonnin Centreville, VA
    edited November 2004
    Red is 5V and Yellow is 12V. An easy way to remember is that the P4 connector, which has extra 12V lines have yellow and black wires.

    The Orange is the 3.3V line.
  • pokesquid808pokesquid808 SO CAL
    edited November 2004
    sounds like your ide controller is going. if your optical isn't working either then either the controller is dead or its going dead. see if you can rma the board.
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