Changed PSU --> XP hangs

By Aggressio · 8 replies
Feb 7, 2006
  1. System:
    MB: Asus K8V SE Deluxe
    CPU AMD Athlon 64 +3400
    MEM: Kingston 1Gb DDR400
    VIDEOCARD: sapphire radeon x800 XT AGP
    PSU: Nexus NX-5000
    STORAGE: 2 sata harddrives+ 2 ide harddrives
    floppy+memorycard reader


    My computer hanged about a month ago, yellow squares appeared on the screen, and no rebooting and turning on/off would help. First I thought that the almost new x800 video card had died but after replacing it with older PCI card I found out that hard-disks weren't found. So in the following panic I tried to figure out what was wrong, and after testing components was pretty sure that the problem was in motherboard or in the cpu. Tried to install the cpu onto a new motherboard and then the system wouldn't start up at all. Cpu and chassis fans turned on, but nothing else happened or nothing appeared on the screen with either video cards. Then I got myself a spare PSU to test the system with, and it turned on as if nothing had happened, ofcourse xp noticed the new motherboard etc. So the problem seemed to be in the antec sonata 380W PSU.


    Then I got myself a brand new nexus NX-5000 PSU. On the box it read 500W but on the label in the unit that is the peak voltage and it should be 460W normally. Ok. It should still be plenty even with all those things inside the machine? So I assembled everything and fired it up. (I had in the panic also cleared CMOS, just in case :p) The windows started fine, though it was a bit slow, and then after few seconds it hung. First mouse pointer stopped and then black screen, and no response to anything but power-switch. The fans work, but screen is empty.

    I tried fiddling around with the BIOS settings and managed to get it to hang even before the windows has started. Different settings seemed to effect a bit on how far it would go on startup. Every now and then I can get even to see my desktop :p.

    The funny thing is, that if I start windows in safe mode, it works like a dream :p Like a safe-mode dream though. Tried to load a restore point, and tried to find every power source settings windows has but no use, it will hang if I try to restart windows in normal mode.

    I've took out the cpu and checked that I put it in there correctly (never tried that before this event) and applied the thermal paste by the book, (little grain of rice...) and managed to get it run a bit hotter (40C with the rice-grain --> 30+C when spreaded the stuff all around the die). But I think it should not be too hot even at 40?. Also checked that memorystick and video card were properly installed.

    So, the fact that it runs in safe mode could indicate software problems? Reinstall windows from scratch? On some forum I read that PSU should provide minimum of 18A to 12V rail, and on that nexus it states maximum of 17,5A? Too low for my cpu?

    I could see my desktop after I disconnected all but the system drive, but it still hanged after a while.

    Trying to repair windows installation when I have managed to install XP on SATA disk is a bit difficult too, since when booting from cd it doesn't find the system drive. After all this fiddling around different things will propably make it necessary to reinstall windows in any case, but i'd like to be sure that this isn't hardware problem before I go on doing that.

    So if anyone has any ideas of what went wrong with my computer and how can I repair it, i would really appreciate any help.

    A friend suggested that the fault still lies on the PSU. Could it be that my cpu eats more amps than the power is capable of. on nexus site it said that maximum load is 15-16 amps...a little low?
  2. Eric Legge

    Eric Legge TS Rookie Posts: 132

    I would install only one stick of RAM, the processor, and the video card to see if the BIOS can be accessed.

    If so, then add only one hard drive with XP on it - or formatted so that you can install XP on it.

    Does the motherboard have the 24-pin connector and the power supply a matching 24-pin connector, or did you fit a 20-pin connector from the power supply to the motherboard?

    And did you connect the additional 4-pin plug to the motherboard from the power supply?

    You should check to make sure that nothing is shorting the board, such as an unused standoff screw under it, etc.
  3. kirock

    kirock TS Rookie Posts: 1,221

    Reinstall Windows from scratch or do a repair. The new mobo is screwinig up your Windows installation. As soon as you get it running in normal mode, update your mobo drivers too.

    Your PSU at 17.5A on 12V is not very good look into buying an Antec or OCZ 450-500W unit. ( I just bought a C R A P generic for a work project and it had 24A on the 12V, and is rated 500W for only $39.00 Canadian).

    Good luck.
  4. wolfram

    wolfram TechSpot Paladin Posts: 1,967   +9

    I think that your PSU is the problem. 18 A in a 12v rail is way too short for your system. Try buying quality PSU´s, like Antecs, Fortrons, etc.
    We can help you choosing a good one.
    Good luck!
  5. Aggressio

    Aggressio TS Rookie Topic Starter

    The psu came with splittable 24-pin connector and I put the 20-pins on the board, and also the 4-pin 12V.

    I'm pretty sure that there are any extra stand-off legs, and i've tried to check if anything else shorts it. Perhaps I'll have to check it again....

    but now when you say that the amps from the PSU ain't enough.
    this is the site for the PSU

    Those maximum loads look pretty bad when looking at my other configuration or do I read them right? When I bought it I was sure that only the wattage counted and bought the box with biggest number on it :p too bad it also had that in the price-label too.

    If you could recommend me another PSU which could actually have enough juice to run my machine, I would appreciate it. Cheap would be nice too :) that AMD athlon 64 seems to be a real power-hog --> 89W Peak...leaves even the x800 radeon with 69W behind it....

    The mobo-switch was temporary, now it's on the original mobo. And the hang isn't normal windows crash, it powers down (the fans rotate though).

    My head is going to explode if the brand new 120€ psu is crap.

  6. Aggressio

    Aggressio TS Rookie Topic Starter

    Do you think that I could try if the amps for the cpu are too low by setting the cpu clock in BIOS to very low, and perhaps the voltage too?

    changing it doesn't do anything. next thing i'll try is booting the thing in safe mode, in which is runs nicely, and trying to put something to load the CPU and see if it hangs in safe mode too...

    i've been trying to find out about what kind of PSU to buy. Found few things saying that psu should provide 20-30A on 12V rail...Checked up Antecs site and found only few models that provided over 20A?. And found some ads for "amd athlon compatible" PSU:s, is the athlon 64 so power hungry that not most of the PSUs can't handle it. The antec supply provided 24A and it broke after a year (Haven't checked what are the manufacturer warranties for it...) so was it under too much strain?

    You promised to help me find another PSU :) so now I could use advice for manufacturers and models that would feed my described system and last for more than a year. And propably be suitable some future updates too...
  7. wolfram

    wolfram TechSpot Paladin Posts: 1,967   +9

    How much can you afford for a PSU?
  8. Aggressio

    Aggressio TS Rookie Topic Starter

    it's not that I could afford anything....

    I would like to get a PSU that will last, and work. but I can't go over 200€.
    I'm mentally preparing myself to spend somethinglike 100€, but I really need
    a PSU that would feed that monster of a CPU, and last for the lifetime of this machine and perhaps be used when I next build a computer...
    so but 20-30A on 12V rail? something like 24 would be minimum since that was the value in my first antec that broke...

    I added myself some bios problems while trying to fix it too :p Unless I Can somehow reset to old BIOS I'm off to buy a new mobo too :p
  9. hewybo

    hewybo TS Maniac Posts: 435

    check this

    Take a look here: It's self explanatory. Should help you decide on a PSU. Also, look here- the first PSU looks awfully good, and Tom's is a good outfit- :)
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