Won't turn on (PSU Works)

Pyro In A Cage · 05-20-2006, 12:11 AM

When I try to turn the computer on, the fans will spin up for about one tenth of a second, and then turn back off. When I try again, it does nothing. If I unplug it and give the capacitors a couple seconds to lse their energy, it will do it again, but will still not turn on.

The power supply (at least partially, pretty sure 100%) works, since all of the motherboard lights stay on (Ethernet, AGP Warn, ETC), and the fans spin up at first.

It is not the power switch, since it does the same thing when I short the 2 power pins with needle-nose pliars.

It is not the RAM, processor, or video card, since I took them all out, and had the exact same problem.

It is not a problem with any of my drives, since I unplug them all and have the same problem.

This leads me to believe that my motherboard is the problem, but I am hoping that somebody here can give me some good new.

Specs:

Processor: P4@2.4Ghz

RAM: 768MB (3 sticks of 256MB DDR)

Video RAM: 64Mb

Motherboard: ASUS Either P4S8X, or P4SBX (I can't tell whether it's an 8 or a B)

Hard Drive: 250Gb SATA

Power Supply: 450 Watts

Cooling: 1 out-take fan in the rear, one intake fan in the front, one processor fan, a power supply fan, 1 hard drive cooler(3 fans), and a chipset fan

**manic** · 05-20-2006, 05:30 AM

You should'nt rule out power supply. I take it the machine was working
ok, then all of the sudden, no worky? Bad thing is , is that sometimes if
a power supply goes it will take other components with it. Usually mobo.
Not always, but it has happened to me. Try to swap out psu, and see
what happens.

~~whodat~~ · 05-20-2006, 08:58 AM

also

inspect the motherboard's capacitors for any leaking or bulged units.

if you have eyes like mine, you will need a magnifing glass and flashlite.

what power supply make is in the machine?

post back

Tumbleweed36 · 05-20-2006, 09:56 AM

Hi,

Either a power supply or you have a short someplace. Take a look around anyplace that your motherboard can be touching the case. Some times, if the tolerance is close, even a small movement of the unit can cause a short if the case is very close to the side of the board.

05-20-2006, 12:11 AM	#1 (permalink)
Pyro In A Cage Registered User Join Date: Apr 2006 Posts: 25 OS: XP	Won't turn on (PSU Works) When I try to turn the computer on, the fans will spin up for about one tenth of a second, and then turn back off. When I try again, it does nothing. If I unplug it and give the capacitors a couple seconds to lse their energy, it will do it again, but will still not turn on. The power supply (at least partially, pretty sure 100%) works, since all of the motherboard lights stay on (Ethernet, AGP Warn, ETC), and the fans spin up at first. It is not the power switch, since it does the same thing when I short the 2 power pins with needle-nose pliars. It is not the RAM, processor, or video card, since I took them all out, and had the exact same problem. It is not a problem with any of my drives, since I unplug them all and have the same problem. This leads me to believe that my motherboard is the problem, but I am hoping that somebody here can give me some good new. Specs: Processor: P4@2.4Ghz RAM: 768MB (3 sticks of 256MB DDR) Video RAM: 64Mb Motherboard: ASUS Either P4S8X, or P4SBX (I can't tell whether it's an 8 or a B) Hard Drive: 250Gb SATA Power Supply: 450 Watts Cooling: 1 out-take fan in the rear, one intake fan in the front, one processor fan, a power supply fan, 1 hard drive cooler(3 fans), and a chipset fan

05-20-2006, 05:30 AM	#2 (permalink)
manic Mod Hardware Team Join Date: Aug 2005 Location: Florida Posts: 5,254 OS: xp	You should'nt rule out power supply. I take it the machine was working ok, then all of the sudden, no worky? Bad thing is , is that sometimes if a power supply goes it will take other components with it. Usually mobo. Not always, but it has happened to me. Try to swap out psu, and see what happens. __________________

05-20-2006, 09:56 AM	#4 (permalink)
Tumbleweed36 Asst Manager Hardware Join Date: May 2005 Location: USA Posts: 19,698 OS: XP Professional	Hi, Either a power supply or you have a short someplace. Take a look around anyplace that your motherboard can be touching the case. Some times, if the tolerance is close, even a small movement of the unit can cause a short if the case is very close to the side of the board. __________________ ---------- I don't receive email notifications of replies to subscribed threads. (Internet provider policy) Therefore, if I don't respond to your post within 24 hours, please send me a reminder PM and include the link to your thread.

05-20-2006, 08:58 AM	#3 (permalink)
~~whodat~~ Register user Join Date: Mar 2005 Posts: 5,931 OS: XP	also inspect the motherboard's capacitors for any leaking or bulged units. if you have eyes like mine, you will need a magnifing glass and flashlite. what power supply make is in the machine? post back