(solved) Comp will not boot up

I recently started getting blue screens, which would reset the bios also. I figured at first that perhaps the psu was dieing or the battery was bad.

I replaced the battery and got a good quality psu (650watt), my last psu was the same wattage but not good quality.

Before the computer would still boot up but give blue screens in heavy graphic use situations like games.

After installing the power supply the computer will no longer boot even to bios. I am sure the psu is installed correctly.

It no longer makes the single beep it used to before loading up.

If I take out the ram the motherboard does beep at me. (long pulses)
I thought perhaps it was the ram then, but no new ram does not help, nor does changing the positions of the ram.

The graphics card is less than a year old, and I've had a gfx card die on me before and it was not the same kind of errors.

The motherboard shows no signs of shorting or damage.

Anyone have any ideas?
11 answers Last reply
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  1. Not getting the single beep means the computer doesn't post (Power On Self Test), indicating you either received a bad PSU or the power cable isn't seated all the way into the MOBO. What happens if you switch back to the old PSU?
  2. Cheers for the reply.
    I did try that also, and same thing, no beep.

    The cords are plugged all the way in.

    I tried turning it on without the graphics card in and all I get is silence.
    I don't know if it should beep at me like it does without ram or not.

    I have a somewhat older nforce 680i motherboard
  3. bios resetting is done either because of unstable bios bootup 3 times or lack of battery. The rest of the problems you include though indicate that you had better had that motherboard checked by the manufacturer.
    Having said that, the computer won't boot if one of your hdds is malfunctioning to the point of sending a current back to the psu. Long beep because of ram could mean your ram is faulty, try changing banks. Each of the symptoms alone could indicate a different problem. The multitude of signs you are getting is mixed, and i think even a very experienced enthusiast would return it to the manufacturer. The only other thing i can propose is breadboarding your rig, but still i don't think i could narrow it down to a single fault.
  4. The beeping only occurs when the ram is out, which I did to try and see if it's a ram problem or a mbo prob. But different ram didn't help. Nor did putting the ram in a different bank.

    The resetting was due I thought to a bad battery and perhaps receiving a pad power supply. Hence changing both battery and psu.

    Question: what should happen if a computer is turned on without a gfx card in it? Bear in mind this is an mbo without on board gfx.
  5. When you are asking for help, always start off with the system specifications.

    However, onward to some systematic troubleshooting techniques.

    Work systematically through our standard checklist and troubleshooting thread:
    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 no luck, 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 (standby power supply): 5 volts always on. The green wire should also have 5 volts on it. It should go to 0 volts when you press the case power button (this is also a good way to test the power switch and the associated wiring), then back to 5 volts when you release the case power switch. 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.
  6. "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. "

    Okay so I get that far and I get silence, however I know that the RAM sticks are fine.

    What then is the next move?
  7. How do you know if the RAM is OK?
  8. Cos it's brand new, strait out of the packet.

    I do have one extra bit of info I just found out.
    I was watching the On Board LED codes as I pressed the power button and it runs through the memory test codes fine but gets stuck at "25" which is the Shadow system/video BIOS code. It gets stuck there with or without the gfx card in.

    So it seems that this is mboard prob yeah?
  9. Oo wait, after searching the error code 25 prob I came across a solution that got me part of the way - the ps2 keyboard being plugged in to the wrong slot. I now get past the 25 code error and get stuck at 7f.
    Have removed the battery and will pit it back soon and try again. If this works I'm going to have a drink to celebrate. If it doesn't I'm going to have a drink to drown my technowoes.
  10. Ok, got it sorted. After once more resetting the bios and reseating all the cards it started up again.
    Who knew that a keyboard plugged in the wrong slot would cause that much trouble...
  11. Whutnz said:
    Cos it's brand new, strait out of the packet.

    All that means is that the RAM is probably good.
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