Bad Motherboard? No post beeps, new power supply.

Hi, I've had a gigabyte motherboard (model: GA-MA790GP-DS4H) for a little over 2 years now about a week ago when i booted it up the boot up screen reported something about a bad hard drive. I got my old hard drive and replaced the current one with it to see if that would solve the issue (after powering down ofc).

Since then I haven't been able to get the computer to boot up at all. No beeps at all the cpu fan starts the video card fan starts etc.

I decided to just throw some money at it and got a new PSU (wrong choice) same thing no beeps. I've tried taking out all the ram sticks but one and did the same with the other 3 and still the same.

Is it safe to assume the motherboards done for? I'm not entirely sure how to test the cpu since I have no other AM3 cpu's on hand to test it with.

Thanks for in advance for any help.
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More about motherboard post beeps power supply
  1. There's a couple things you should try first. Take the video card out and try it, or take the motherboard battery out for a little bit and put it back in, and also disconnect all CD drives, hard drives, etc. and try it. Btw welcome to the forums!
  2. Go through the troubleshooting sticky. Link in my sig.

    Make sure you have a case speaker, or no beeps.

    Check to see if you forgot to connect a 6 or 8 pin to GPU, or a 4 or 8pin to mobo. Also check connection to monitor, if you're using an adapter, maybe an issue there, etc.
  3. Thanks for the welcome, i forgot to mention i tried booting up with no cd-rom hardrives etc.

    I'll try the battery as a last ditch effort.
  4. Work systematically through our standard checklist and troubleshooting thread:
    (This is what banthracis linked to in his sig)
    I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

    If that doesn't help, continue.
    The following is an expansion of my troubleshooting tips in the breadboarding link in the "Cannot boot" thread.

    I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different, but they all use a single short beep for a successful POST.

    Breadboard - that will help isolate any kind of case problem you might have.

    Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.

    Make sure you plug the CPU power cable in. The system will not boot without it.

    I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case once you are finished.

    You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

    If no beeps:
    Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.

    At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

    The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

    You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.

    A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.

    This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

    If the system beeps:
    If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card.

    Silence, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.

    Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.
    At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.

    Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
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