ATX versus ATX12V Power Supply for nForce2 mainboard?

I bought a new Abit NF7-S2 nForce2 motherboard with Athlon XP 2600+ but
cannot seem to get it to work with either of my ATX power supplies. The
power LED lights showing the board has power but when I press the power
switch the fans just quiver and nothing happens. (Fans on CPU and PS
move as if about to start and I hear an inductor charge up.)

Does this sound like I need to buy an ATX12V power supply? Or a bad
board? I bought the connector to convert a 4-pin linear molex connector
to a 4-pin square connector but it seems to only use two pins from the
linear to output to four in the square though Tom's HW claims the
output is a 5V, 3.3V and ground I think.

Thoughts? Cannot seem to get the vendor or Abit to reply. And bought to
use not play with and ship back!

Thanks a bunch,
TimJowers

Tim wrote:
I bought a new Abit NF7-S2 nForce2 motherboard with Athlon XP 2600+
but cannot seem to get it to work with either of my ATX power
supplies. The power LED lights showing the board has power but when I
press the power switch the fans just quiver and nothing happens.
(Fans on CPU and PS move as if about to start and I hear an inductor
charge up.)

Does this sound like I need to buy an ATX12V power supply? Or a bad
board? I bought the connector to convert a 4-pin linear molex
connector to a 4-pin square connector but it seems to only use two
pins from the linear to output to four in the square though Tom's HW
claims the output is a 5V, 3.3V and ground I think.

Thoughts? Cannot seem to get the vendor or Abit to reply. And bought
to use not play with and ship back!

Thanks a bunch,
TimJowers

Your kidding, right?

That crap has not worked right since ASUS and others tried the smart plug
bull****. More than likely your power supply is woefully underated to the
task at hand. Stick a crowbar in your wallet, get a real power supply and
it will PROBABLY work. No guarantees since you have muked around with this
baloney.

S

Until you measure voltages and provide useful numbers, then
every answer will be only wild speculation. No one can read
your mind or see that setup. You cannot see electrons nor feel
that current is sufficient. Get the meter which every
responsible computer repairman has. First get numbers.

Note the numbers AND how those numbers change with pressing
power switch. Do some voltages rise up only for less than 2
seconds when the power switch is pressed? Numbers tell us
useful information. Procedures to get useful information
previously posted as "I think my power supply is dead" in
alt.comp.hardware on 5 Feb 2004 at
http://www.tinyurl.com/2musa and
"Computer doesnt start at all" in alt.comp.hardware on 10
Jan 2004 at
http://tinyurl.com/2t69q

Tim wrote:
I bought a new Abit NF7-S2 nForce2 motherboard with Athlon XP 2600+ but
cannot seem to get it to work with either of my ATX power supplies. The
power LED lights showing the board has power but when I press the power
switch the fans just quiver and nothing happens. (Fans on CPU and PS
move as if about to start and I hear an inductor charge up.)

Does this sound like I need to buy an ATX12V power supply? Or a bad
board? I bought the connector to convert a 4-pin linear molex connector
to a 4-pin square connector but it seems to only use two pins from the
linear to output to four in the square though Tom's HW claims the
output is a 5V, 3.3V and ground I think.

Thoughts? Cannot seem to get the vendor or Abit to reply. And bought to
use not play with and ship back!

Thanks a bunch,
TimJowers

Thanks man. You are right, ATX12V boards are not backwards compatible
with power supplies. I bought the new PS and it worked. The symptoms
were the same as having a short such as a blown floppy disk. I guess
nForce must need a certain high enough bias voltage to boot and ATX
power supplies do not provide that. Wonder if they have a comparator
restricting starting like the new autos when the battery is weak....
well so far the Athlon 2600 feels lightning fast compared to the Compaq
1800 Celeron notebook and even feels faster than my dual 450 (which was
always faster than the Compaq). I'll read around here for what
benchmarks to use.

Tim wrote:
Thanks man. You are right, ATX12V boards are not backwards compatible
with power supplies. I bought the new PS and it worked. The symptoms
were the same as having a short such as a blown floppy disk. I guess
nForce must need a certain high enough bias voltage to boot and ATX
power supplies do not provide that. Wonder if they have a comparator
restricting starting like the new autos when the battery is weak....
well so far the Athlon 2600 feels lightning fast compared to the
Compaq 1800 Celeron notebook and even feels faster than my dual 450
(which was always faster than the Compaq). I'll read around here for
what benchmarks to use.

Sorry Tim if I was a bit of a "Richard Noggin" if you know what I mean.
It's just frustrating to see manufacturers push this line of baloney on the
public. The amount of old ATX power supplies that can actually push a
modern board are few and far between with these so called "smart plugs". A
load of crap they are, as you have seen.

Anyway, I am glad you got it running. Power supplies are probably the most
overlooked component in a computer system. Why invest in a decent
motherboard/cpu/ram/video card set just to kill it with a cheap unit?

I am no expert, but I do know this: You get what you pay for!

S