PC switching itself on!

[TheBigBasicQ]

Hi, I recently purchased an Intel 2.8C GHz HT 800MHz FSB processor and Intel D865GBF motherboard. The problem i am facing is that when i turn on my mains the computer switches itself on. This happens occassionally. But when this happens my computer doesnt boot. It just freezes up at the POST. On other occassions the computer doesnt switch on itself. But rather the HDD/Power LEDs glow, the HDDs start to power up, the cabinet & cpu fans start spinning. This happens momentarily. Its like quickly switching on the system and then turning it off immediately. When this happens I can turn on my PC using the front panel and the system works fine. What is the problem? I have heard many people face this exact same problem. One of my friend used an ASUS board which used the intel 865 chipset and had the same problem. He just replaced the mobo and everything worked fine.

I tried doing the following:

1. I replaced my mobo but it didnt make any difference.

2. I changed the PSU & the power switch(front panel)

3. I removed all the cards(gfx acclerator and the LAN card) and then tried booting the system. Didnt work =(

4. Upgraded my BIOS.


My detailed configuration is:
---Hardware
Intel 2.8C GHz HT 800MHz FSB processor
Intel D865GBF motherboard
ATi Radeon 7000 64MB GFX accelerator
256MB DDR RAM
20GB Segate HDD
Realtek 8129 LAN card

---Software
Windows ME
Redhat Linux 9.0 (dual boot)

Another peculiar problem i noticed was when i disconnected all the connections of the front panel from the mobo, still the computer would switchon itself. How come this is possible? If I havent connected the power switch(or HDD/Power LED connectors or Reset Button connector) still the computer switches on itself!

Thanks

PS: forgot to mention i was using a 300W PSU. Should a 350W supply make any difference?

Nobody is perfect =(
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I am nobody =D

 

[Lemon13]

check your bios settings in power management-restore on power loss. should not be set to power on.

 

[micker377]

Check that the modem is not set to power up on ring. Same for the NIC card. These can be found both in the BIOS setup and the setup for the individual cards. Check "Task Schedular" to see if anything would try to run at the times it "self-boots".

 

[TheBigBasicQ]

Yes I turned off all such settings. It had something called as ACPI. Whats that? I turned off Power On on ring, NIC cards and all those options where i could find "Power On". But its still giving me that problem =(.

Could there be a remote chance that my 300W PSU is insufficient and a 350/400W PSU is required? I've got 2 HDDs, 1 CDRW, 1DVD-ROM, Speakers, GFX acclerator and NIC card in there.

How do I find out how many amperes is the PSU? I checked out Intels website where it said that we should be ideally using 8A PSU instead of a 5A one.

http://support.intel.com/support/motherboards/desktop/sb/CS-009014.htm

Have a look at that link.

Nobody is perfect =(
.
.
.
.
I am nobody =D

 

[micker377]

ACPI should be left on - otherwise the computer won't shut down properly. Unless the "signal" line of the P.S. is bad, the P.S. shouldn't cause this problem. You can try (borrow) another one to check it out for peace of mind.

 

[TheBigBasicQ]

Ok, I left it on. But what do you think about the PSU?

Nobody is perfect =(
.
.
.
.
I am nobody =D

 

[paparazi]

I would still say the power supply is the most likely, or a loose connection somewhere causing spikes, loose fuse, loose plug terminal, that kind of thing.
Martin


Replying helps further our knowledge, without comment leaves us wondering.

 

[freakypervsd]

The Power Switch Maybe stuck, some switches have that really tiny button behind a bigger switch...

my 2 cents,

...Everybody is Somebody

 

[micker377]

Have you tried the board outside the case? Mobo - power supply and video board. You'll get an error (no operating system). Also, some boards have "keyboard on". Make sure (in BIOS - power) that this is set to "button only". You can even set the BIOS to ignore keyboard error and leave the keyboard unplugged.

 

[TheBigBasicQ]

I havent actually removed the whole setup and put it on a card board. But I have put a plastic sheet behind the mobo to insulate it from the metal surfaces of the case. But it didnt work. I will try it outside on a cardboard if you feel that my solution was insufficient.

Also, I dont have a keyboard on option in the bios. I have turned off all the power management settings which had a "Power On" option.

Nobody is perfect =(
.
.
.
.
I am nobody =D