new PC build powers off after a half-second

[rgonzale6]

Ok, I'm throwing together my new build today. I had to go out and buy
a new power supply because my mobo has a 24-pin (BTX or EATX I guess)
connection and I only had a 20-pin (ATX) connection. I've pieced my
system together. Put some arctic silver between the heatsink and the
CPU and the whole deal.

I got to power it on...and it it looks like it powers up for a
half-second and then does nothing. I then turn it off and on at that
point and nothing happens. I disconnect power cables and turn off
master switch on PSU, then reconnect everything and turn it back on and
the loop repeats itself starting with the half-second of power.

I've checked the power switch/mobo connections and it seems they're
connected correctly. Also, there's been no tell-tale (thankfully)
smell of burnt electronics at any time.

There aren't many components to power, as I only have a gfx card as a
slotted card. Also, two HDs and a CD drive along with 3 internal fans.

Anybody have any ideas? My PSU is a MadDog SurePower 400W BTX/ATX.
Mobo is a Asus A8N-SLI. Case is a CoolerMaster ATCS. Both mobo power
cables are connected to the mobo. *Any* help would be great.

Thanks!

 

[ohaya]

Ok, I'm throwing together my new build today. I had to go out and buy
a new power supply because my mobo has a 24-pin (BTX or EATX I guess)
connection and I only had a 20-pin (ATX) connection. I've pieced my
system together. Put some arctic silver between the heatsink and the
CPU and the whole deal.

I got to power it on...and it it looks like it powers up for a
half-second and then does nothing. I then turn it off and on at that
point and nothing happens. I disconnect power cables and turn off
master switch on PSU, then reconnect everything and turn it back on and
the loop repeats itself starting with the half-second of power.

I've checked the power switch/mobo connections and it seems they're
connected correctly. Also, there's been no tell-tale (thankfully)
smell of burnt electronics at any time.

There aren't many components to power, as I only have a gfx card as a
slotted card. Also, two HDs and a CD drive along with 3 internal fans.

Anybody have any ideas? My PSU is a MadDog SurePower 400W BTX/ATX.
Mobo is a Asus A8N-SLI. Case is a CoolerMaster ATCS. Both mobo power
cables are connected to the mobo. *Any* help would be great.

Thanks!

Hi,

To diagnose, disconnect everything, except leave the video card and one
memory stick only connected. Connect the power switch leads, reset
leads, power LED leads, and speaker leads.

Do you hear any beeps? Report back on this, and if you hear beeps, they
will be a set of long/short beeps, so report the sequence of beeps.

It sounds like it's shutting due to overheating.

I know that you said that you used Arctic Silver, but is there any
chance that you mounted the heatsink backwards/reversed? One end of the
bottom of the heatsink is notched/higher, and that should match the
socket. If the heatsink is mounted backwards, it won't be contacting
the CPU.

Jim

 

[Wookie]

Does your CPU Fan spin at power up? .. some boards will power off instantly
if the fan is not on.

 

[KLB]

I have had this problem before, turned out to be that when I has connected
the power to my floppy drive I had caught three pins rather than four. If
you have a floppy drive then check this. If not then check all power supply
leads and ensure that all are connected.

 

[dr ratt]

Ok, I'm throwing together my new build today. I had to go out and buy
a new power supply because my mobo has a 24-pin (BTX or EATX I guess)
connection and I only had a 20-pin (ATX) connection. I've pieced my
system together. Put some arctic silver between the heatsink and the
CPU and the whole deal.

I got to power it on...and it it looks like it powers up for a
half-second and then does nothing. I then turn it off and on at that
point and nothing happens. I disconnect power cables and turn off
master switch on PSU, then reconnect everything and turn it back on and
the loop repeats itself starting with the half-second of power.

I've checked the power switch/mobo connections and it seems they're
connected correctly. Also, there's been no tell-tale (thankfully)
smell of burnt electronics at any time.

There aren't many components to power, as I only have a gfx card as a
slotted card. Also, two HDs and a CD drive along with 3 internal fans.

Anybody have any ideas? My PSU is a MadDog SurePower 400W BTX/ATX.
Mobo is a Asus A8N-SLI. Case is a CoolerMaster ATCS. Both mobo power
cables are connected to the mobo. *Any* help would be great.

Thanks!

check that you only have stand-off pegs under the screw holes in your
mobo.
the only time i've ever had this problem was when i put a new mobo in
my old full tower case & it had 1 less hole than the previous board.
the peg caused a short which was immediately detected reulting in
shutdown.

dr ratt

------------------------------------------------------------
gary: so there's no chance we can be together?
lisa: only if you promise me you'll never die.
gary: you know i can't promise that.
lisa: if you could do that, i'd make love to you, right now.
gary: i promise. i will never die.

 

[jime]

My guess is there is a power cable connected wrong.
Remove all but the mobo. Only have the power to the board. Short the pins
that the start switch would. See if it holds power.
I had a problem just like this and a 4 pin connector was installed wrong.
Good luck.
Jiim

 

[Pete Gray]

Ok, I'm throwing together my new build today. I had to go out and buy
a new power supply because my mobo has a 24-pin (BTX or EATX I guess)
connection and I only had a 20-pin (ATX) connection. I've pieced my
system together. Put some arctic silver between the heatsink and the
CPU and the whole deal.

I got to power it on...and it it looks like it powers up for a
half-second and then does nothing. I then turn it off and on at that
point and nothing happens. I disconnect power cables and turn off
master switch on PSU, then reconnect everything and turn it back on and
the loop repeats itself starting with the half-second of power.

I've checked the power switch/mobo connections and it seems they're
connected correctly. Also, there's been no tell-tale (thankfully)
smell of burnt electronics at any time.

There aren't many components to power, as I only have a gfx card as a
slotted card. Also, two HDs and a CD drive along with 3 internal fans.

Anybody have any ideas? My PSU is a MadDog SurePower 400W BTX/ATX.
Mobo is a Asus A8N-SLI. Case is a CoolerMaster ATCS. Both mobo power
cables are connected to the mobo. *Any* help would be great.

Thanks!

You didn't mention which video card you were using, but if it requires
a separate power connector, did you connect it. I forgot to connect
the power lead to the video card once and had the same symptoms.

 

[rgonzale6]

My guess is there is a power cable connected wrong.
Remove all but the mobo. Only have the power to the board. Short the pins
that the start switch would. See if it holds power.
I had a problem just like this and a 4 pin connector was installed wrong.
Good luck.
Jiim

After bare-bones-ing the system and adding a component back in a piece
at a time, I found the problem to be in a lighted case fan that I had.
I removed that from the system and it powered up normally. System has
been stable ever since.

Thanks a bunch to everyone who helped me out!

Rich