a7n8x-e deluxe POST questions

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

I've got some issues with an a7n8x-e deluxe that I've bought as used in
a local computer store.

Please consider that I've read some of the threads in the group about
the matter but I've still some questions.

I tested the board with nothing mounted on it and placing it on a
cardboard as said in some previous post, to ensure that no case
shortcuts will occour.

My PSU is a Takey TK-400W2f that worked fine with another system
(a7v333 + athlon XP 2000 fsb266 + 2x512 geil pc2700 DDR).

When I power on the a7n8x-e the green led on the m/b lights fine and I
get the regular post message: no cpu installed.

Then I mounted the cpu, an used athlon XP 2400 + fsb 266 that I've
bought on ebay (sigh) as 'to be tested'. When I power the m/b the cpu
fan spins but the m/b do not post.

So I've used another cpu, an athlon XP 2000+ that I know was
functional, but nothing at all, no voice post message. When I remove
the processor the post message come up. Consider that no keyboard or
mouse or case connectors are plugged to the m/b, I start the system by
shorting the power-on pins on the system panel connector with a
screwdriver.

Should I test the motherbord plugging mouse and keyboard and mounting
memories?

Why I can't get a post message when a processor is mounted on the m/b?

Should a faulty processor always be signaled by a post voice message or
in some case it is not possible?

I've also cleared the CMOS as recommended in some previous message.

When I test the used athlon XP 2400 bought on ebay in my working a7v333
I get the post voice message indicating the CPU failure so probably
this particular CPU is broken.

What scare me now is that I do not know if the m/b a7n8x is working. I
want to buy a new athlon XP 3000 fsb 333 to use with it, but I'm scared
that the a7n8x could damage the brand new CPU. I could not test it on
the a7v333 because it does not support it and I need this other system
for work, so I fear testing the working cpu again on the a7n8x.

Could a faulty m/b burn the new cpu or I can test the a7n8x with it
without fearing nothing related to a faulty motherboard? It has a six
months warranty so I can return it back if I can prove it is damaged.

Thank you for your patience; forgive me for my 'spaghetti english'.

Best regards
n
3 answers Last reply
More about a7n8x deluxe post questions
  1. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    Hi Paul,
    thank you for your very comprehensive reply.

    You have enlightened me about how this particular hardware works and
    I'll read carefully what you wrote in your previous posts.

    I'll get a voltmeter and try the measures you suggest.

    The Takey specs written on the side of the PSU box are:

    +3.3V 14A
    +5V 30A
    +12V 16A
    -5V 0.3A
    -12V 0.5A
    +5Vsb 2A

    So it should be adequate, but ... I'll test it with the voltmeter.
    And probably I'll get a new powerfull and reliable PSU taking in mind
    further upgrades of the system.

    I've ordered a brand new athlon XP 3000+, it will be here in a few
    days.
    >From your reply I do not have understood if I should trust the
    motherboard do not burns my new cpu if it (the m/b) is broken? Or you
    suggest that I'll find a cheap and old CPU like a Duron to make these
    tests?

    Thank you again,
    n.
  2. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    In article <1121631154.565477.56060@g43g2000cwa.googlegroups.com>, "n"
    <nicoletta_uroborea@hotmail.com> wrote:

    > I've got some issues with an a7n8x-e deluxe that I've bought as used in
    > a local computer store.
    >
    > Please consider that I've read some of the threads in the group about
    > the matter but I've still some questions.
    >
    > I tested the board with nothing mounted on it and placing it on a
    > cardboard as said in some previous post, to ensure that no case
    > shortcuts will occour.
    >
    > My PSU is a Takey TK-400W2f that worked fine with another system
    > (a7v333 + athlon XP 2000 fsb266 + 2x512 geil pc2700 DDR).
    >
    > When I power on the a7n8x-e the green led on the m/b lights fine and I
    > get the regular post message: no cpu installed.
    >
    > Then I mounted the cpu, an used athlon XP 2400 + fsb 266 that I've
    > bought on ebay (sigh) as 'to be tested'. When I power the m/b the cpu
    > fan spins but the m/b do not post.
    >
    > So I've used another cpu, an athlon XP 2000+ that I know was
    > functional, but nothing at all, no voice post message. When I remove
    > the processor the post message come up. Consider that no keyboard or
    > mouse or case connectors are plugged to the m/b, I start the system by
    > shorting the power-on pins on the system panel connector with a
    > screwdriver.
    >
    > Should I test the motherbord plugging mouse and keyboard and mounting
    > memories?
    >
    > Why I can't get a post message when a processor is mounted on the m/b?
    >
    > Should a faulty processor always be signaled by a post voice message or
    > in some case it is not possible?
    >
    > I've also cleared the CMOS as recommended in some previous message.
    >
    > When I test the used athlon XP 2400 bought on ebay in my working a7v333
    > I get the post voice message indicating the CPU failure so probably
    > this particular CPU is broken.
    >
    > What scare me now is that I do not know if the m/b a7n8x is working. I
    > want to buy a new athlon XP 3000 fsb 333 to use with it, but I'm scared
    > that the a7n8x could damage the brand new CPU. I could not test it on
    > the a7v333 because it does not support it and I need this other system
    > for work, so I fear testing the working cpu again on the a7n8x.
    >
    > Could a faulty m/b burn the new cpu or I can test the a7n8x with it
    > without fearing nothing related to a faulty motherboard? It has a six
    > months warranty so I can return it back if I can prove it is damaged.
    >
    > Thank you for your patience; forgive me for my 'spaghetti english'.
    >
    > Best regards
    > n

    Your Takey power supply is made by Leadman. It could be there is
    not enough current on +5V available. +5V at 20A-25A is a good
    starting point. I cannot find any specs on the supply.

    The Winbond speech chip has 6 hardware event triggers and 127
    software event triggers. The SLOTOCC# pin is grounded when a CPU
    is inserted in the socket. With the CPU removed, that is why
    you get the "No CPU" message.

    When the CPU is inserted, one would hope the BIOS code starts
    to run.

    Looking at the program code for the Speech chip again, it looks
    like CPU fail is hooked to a hardware signal, but exactly what
    that might be, is anyone's guess. (In the program code, vector 66
    likely corresponds to hardware signal number 3. Winbond datasheets
    are always a mess, and the vector assignments shown in the datasheet
    don't exactly correspond to the program code. The datasheet shows
    vector numbers 1-5 while the program code starts at 64 for those
    signals.) The two program files I've been able to find, are shown
    in this post.

    http://groups.google.ca/group/alt.comp.periphs.mainboard.asus/msg/af9eb7c50228db72?dmode=source&hl=en

    When you plug in a CPU and the Voice POST is quiet, it means
    the hardware signal #3 did not trigger. I thought the Winbond
    chip was using timers to detect some failure modes, while for
    the vast majority of error messages (vectors 128 and higher),
    the speech samples are triggered by the processor writing the
    vector number to the Winbond chip. I'm having trouble understanding
    how the first few events work, because the Winbond datasheet does
    not address the programming language or register map used by the CPU
    inside the Winbond chip. (The flash chip with the Voice samples
    in it, contains not only voice samples, but also the program
    code in the two sample files in my post above.)

    Regarding your test procedure, I think plugging mouse, keyboard,
    memory, video card is a good thing to do. I would get a voltmeter
    and measure the voltages from the PSU while the computer is
    powered and the fans are spinning. You might notice a voltage
    that is out of spec. If you don't have a voltmeter, swap another
    power supply (one that has at least 20 amps available on +5V).
    The power supply specs are normally printed on a label on the
    side of the supply. The A7N8X-E Deluxe draws most of its power
    from +5V, so a supply that is strong on that rail will help.

    I would find a processor that works in your A7V333, then use
    that known good processor, to test the A7N8X-E. When it has
    adequate power, it might start.

    Motherboards are very complicated circuits, and it is miraculous
    that so few complicated fault modes manifest themselves for
    the vast majority of users.

    HTH,
    Paul
  3. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    In article <1121713772.241426.29420@g44g2000cwa.googlegroups.com>, "n"
    <nicoletta_uroborea@hotmail.com> wrote:

    > Hi Paul,
    > thank you for your very comprehensive reply.
    >
    > You have enlightened me about how this particular hardware works and
    > I'll read carefully what you wrote in your previous posts.
    >
    > I'll get a voltmeter and try the measures you suggest.
    >
    > The Takey specs written on the side of the PSU box are:
    >
    > +3.3V 14A
    > +5V 30A
    > +12V 16A
    > -5V 0.3A
    > -12V 0.5A
    > +5Vsb 2A
    >
    > So it should be adequate, but ... I'll test it with the voltmeter.
    > And probably I'll get a new powerfull and reliable PSU taking in mind
    > further upgrades of the system.
    >
    > I've ordered a brand new athlon XP 3000+, it will be here in a few
    > days.
    > >From your reply I do not have understood if I should trust the
    > motherboard do not burns my new cpu if it (the m/b) is broken? Or you
    > suggest that I'll find a cheap and old CPU like a Duron to make these
    > tests?
    >
    > Thank you again,
    > n.

    OK. To review your test results, you do have one good processor
    that works in your A7V333. Use the good processor to test the
    A7N8X-E. Insert the good processor and see if it will run. Then,
    remove the processor from the A7N8X-E socket, and put the processor
    back in the A7V333 for another test. If the processor is still
    working, it means the A7N8X-E is not killing processors.

    If, after trying that good processor in the A7N8X-E, the processor
    will no longer work in the A7V333, then you know the A7N8X-E
    motherboard is a "chip killer", and no further testing of the
    A7N8X-E should be attempted.

    From an budget perspective, it is better to measure the Takey
    supply with a voltmeter, rather than blindly replace it. Test it
    while it is loaded with the A7N8X-E, good processor, stick of
    memory, keyboard, mouse, video card etc. If the voltages
    are within 5% of nominal 3.3V, 5V, 12V, then it could be the
    A7N8X-E motherboard is defective. If the power supply is showing
    any signs of instability or overload (burning smell, funny sounds
    from inside the supply, unstable voltages), replace it immediately.

    As long as some of the components remain alive, you should be
    able to narrow down what is wrong.

    HTH,
    Paul
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