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    Boot Problem - 2 Beeps at POST


    After 3 problem-free years with my computer, I'm now having boot problems. I get 2 beeps at POST which supposedly means parity circuit failure. I tried playing with the RAM (make sure it seated properly, tried different slots, tried different memory sticks) but that wasn't the problem. I thought it might be the motherboard so I replaced the MOBO and also purchased new RAM.

    Last night the problem returned.....the house power flickered for a second, the computer went down and then tried to re-boot itself but couldn't. It just gave the two beeps. I completely shut it down for about five minutes then came back and tried booting it and it booted fine. This has happened in the past also where the house power flickers, computer won't re-boot, turn it off for 5-10 minutes and then it starts fine. The problem has also occurred on some cold boots in the morning but that is pretty rare.

    It's obviously not the MOBO or RAM. What else can cause the 2 beeps? Any thoughts? Thanks.
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    (^^;?(How do we know that without info. Beep code is defined by Bios.)

    Consult your mobo maker and search about its bios.
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    About beeps

    If the computer beeps the same tone over and over again (Award/Phoenix BIOS) or beeps in series of three (AMI BIOS), then you may have a problem with memory. The most likely scenario is that the memory is not all of the way in the slot. JUST BECAUSE the white retention tabs snap up into the locked position, does not mean that the RAM is all of the way in the DIMM slot. The board can bow, and the DIMM may not be seated in the center. On AMI BIOS based boards, this error code is a series of three beep, three beeps, three beeps, in a continuous loop.

    If the computer beeps one long beep and then two short beeps (Award/Phoenix BIOS) or eight short beeps in a row (AMI BIOS), this is a video card error. Check to make sure the video card is fully seated. If problem persists, try another video card. If the computer beeps a high tone, followed by a low tone, and then repeats (Asus motherboard), make sure that the CPU fan is plugged into the header labeled "CPU FAN" and not one of the other provided.

    Here's some other beep codes:

    Award and Phoenix BIOS:

    1 short beep: Normal
    2 short beeps: CMOS error
    1 long and 1 short beep: DRAM error
    1 long and 2 short beeps: Video card error
    1 long and 3 short beeps: Keyboard error
    1 long and 9 short beeps: ROM error
    Long continuous beeps: DRAM not installed correctly
    Short continuous beeps: Bad power supply


    1 short beep: DRAM flash error
    2 short beeps: DRAM ECC check error
    3 short beeps: DRAM detect error
    5 short beeps: CPU error
    6 short beeps: Keyboard error
    8 short beeps: Video card error
    9 short beeps: ROM error
    1 long and 3 short beeps: Bad DRAM
    1 long and 8 short beeps: Video card error

    Invoking Beep Codes

    No beeps AND no POST? Pull everything out of the machine except for the CPU (with a cooling fan, of course) and power the PC up. The PC should now only consist of a power supply, a motherboard and a CPU/HSF. This means your PC should have no video card, RAM or IDE cables. You should have no PCI cards and that includes modems and sound cards. Have a power button and speaker hooked up to the board so you can turn it on and listen for beep codes.

    If you have the PC stripped down this much and you STILL do not get any beep codes, then you may have an issue with either the CPU, motherboard or power supply. This is easy to conclude as you only have these three parts left in your system.

    If the computer is actually functioning and the computer beeps continuously, then there is a problem with a voltage on the power supply being incorrect or the CPU overheating. IMMEDIATELY go into the BIOS and check CPU temperature, fan speed and voltages

    BIOS Beep Codes

    Annoying isn't it? You have built your computer you switch it on and then nothing happens except a few beeps from the PC speaker. Frustration sets in as you try to figure out what is wrong with it. If you didn't already know the computer has already told you the problem. It can't speak of course but it can direct you to the problem. Its all in the beeps. The BIOS can recognise when the problem occurs and sends a signal out to send a certain amount of beeps through the speaker. These beeps then tell you the location of the problem.

    Unfortunately not all the BIOS' use the same codes as each other. Two of the main BIOS manufactures AMI and Award (now Phoenix) have different codes for there errors.


    # of Beeps Error Description
    1 Refresh Failure The memory refresh Circuitry is faulty
    2 Parity Error Parity error in the Base (1st 64K) of memory
    3 64K Base Memory Error Memory error in the base memory (1st 64K)
    4 Timer Not Operational Timer 1 is not functioning (also caused by error in base memory)
    5 Processor Error CPU error
    6 8042 Gate A20 Failure Unable to switch to protected mode
    7 Processor Exception Interrupt error The CPU on the CPU card generated an interrupt error
    8 Display Memory Read/Write Error Video adapter is missing, incorrectly seated or has faulty memory
    9 ROM checksum error The ROM checksum does not match that of the BIOS
    10 Coms Shutdown Register Read/Write The shutdown register for coms RAM has failed
    11 Cache Memory Bad The cache memory test has failed. Cache memory will be disabled. *** DO NOT enable it ***

    With the first 3 beep codes, its well worth re-seating the memory just to make sure that it's in correctly. 8 Beeps is probably the most common in my experience. Can be caused by a badly seated Graphics card. If you have re-seated it then check with another Graphics card in the board.

    Always check for loose components before sending the board back as this is the main cause of errors on the POST.

    Award BIOS

    Award states that they now only use one beep from there BIOS. This beep is one long beep and then two short beeps. This indicates a graphics card problem. Any other beeps should be treated as a RAM problem first and then the board sent in to be inspected.

    The reason that the Award BIOS only uses the beep code for display problems is that it tries to display the error on-screen if at all possible. If the BIOS cannot initiate the display adapter then this causes the BIOS to make the beep code for a display error, which must be corrected before any other errors can be determined. Memory Test fails and hard disk failures etc will all be displayed on screen


    The IBM BIOS works with Short and Long beeps as well as the Award BIOS. However the IBM one does still have codes to work from.

    Beep Code Error
    1 Short Beep Normal POST, System booted OK
    2 Short Beeps POST Error - Code on Display
    No Beep Power supply or Motherboard error
    Continuous Beep Power supply or Motherboard error
    Repeating short beeps Power supply or Motherboard error
    1 short, 1 long beep System board error
    1 long, 2 short beeps Display adapter error (MDA/CGA)
    1 long, 3 short beeps Display adapter error (EGA/VGA)
    3 long beeps 3270 keyboard card

    Phoenix BIOS
    The Phoenix BIOS works on a slightly more complicated manor than the others. It does display an error code for you and produce a series of beeps. This BIOS produces its beeps according to the hexadecimal code the error produces. The Phoenix BIOS has many different codes for its possible errors and so many different beep codes. Rather than list the entire section here, I have provided a link to the official PDF file containing the codes and how they are derived.

    Phoenix BIOS Post Codes

    System board errors should be looked at by a specialist, Again always try to re-seat components to ensure they are in correctly. If necessary take all components out except for the RAM CPU and graphics card, then try the system. Re-seating components is the number one fix for getting past the POST screen. One badly seated components can cause the entire system not to function.


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