ASUS A7V8X-X & AMD Sempron 2400+

[DONNY]

I am trying to build a new PC using the Asus A7V8X-X motherboard,
Sempron 2400+ and Kingston 256MB 333Mhz PC2700 DDR memory with no
success. Have tried AGP & PCI video cards. The system will not boot
at all; not even into the BIOS. I have tried different memory with no
luck. The power supply & CPU fans will start for about 1-2 seconds and
then turn off with no visual. Should I suspect defective products and
if so what is the most likely item. All products are new. The PSU
light remains green on the motherboard. Thank you for any suggestions.

 

[Paul]

I am trying to build a new PC using the Asus A7V8X-X motherboard,
Sempron 2400+ and Kingston 256MB 333Mhz PC2700 DDR memory with no
success. Have tried AGP & PCI video cards. The system will not boot
at all; not even into the BIOS. I have tried different memory with no
luck. The power supply & CPU fans will start for about 1-2 seconds and
then turn off with no visual. Should I suspect defective products and
if so what is the most likely item. All products are new. The PSU
light remains green on the motherboard. Thank you for any suggestions.

A BIOS can shut down if no CPU fan is detected when the BIOS
first starts execution. But you say the fan is spinning, and
one would hope it is spinning fast enough.

Another possibility, is the heatsink is on backwards. There are
two orientations, one being a 180 degree rotation from the other.
If the contact patch on the bottom of the heatsink, is not aligned
with the silicon die, part of the die is uncovered by metal, and
that part of the die will overheat quickly. Examine the heatsink
and make sure the contact patch is centered over the die. Also
verify that the thermal paste or pad is making good contact.
If you put a tiny dot of paste on the die, then lower the
heatsink onto it, the dot of paste should spread in a
circle, indicating good contact pressure. Using the tiny dot
will also allow you to calibrate how much paste is required.
Paste should be applied in a thin coat, but enough should be
used, so that it wets the edge of the die when in place. If it
gushes out the sides, that is too much.

In terms of power, the board will use mostly +5V or +3.3V, so
I would want at least 20 amps capability on +5V, to help rule
out that this is a power supply problem.

HTH,
Paul