WEIRD POWER PROBLEM - please help

[Perfect Dark]

Okay, so I went on a 5 day vacation. My computer was off but
everything still plugged in, I come back after the fifth day (there
were no thunderstorms in the meantime and my other computer still
works fine) and The computer would not turn on. The light on the
motherboard was still lit (still getting power) but the power supply
fans would not start, nothing does anything. When I fooled around with
some stuff (i.e. turned the switch on the power supply from 1 to 0
then back to 1) the fans started to whir for a second without having
touched the soft power button in the front and then it sounded like a
small jet engine starting up and then dying.
So I figured, Hey, must be a dead power supply, so I ordered a brand
spanking new Thermaltake from new egg with a higher wattage (480).
Plugged it up and Voilla, computer still doesnt turn on...So does
anyone have any ideas?

Motherboard: ASUS A7V600
Processor: AMD ATHLON XP 2.01 GHZ
SATA 120GB harddrive, 80 GB IDE Harddrive.

The motherboard light is still on but powersupply doesnt turn on. The
only thing that comes to mind would be that the system panel connector
wires from the front ATX Power Switch/Soft are bad but I didn't touch
them from 5 days ago! and The computer has been working fine for 8
months now.

Okay, I'm rambling...who knows what's going on?
Thanks

 

[Paul]

Okay, so I went on a 5 day vacation. My computer was off but
everything still plugged in, I come back after the fifth day (there
were no thunderstorms in the meantime and my other computer still
works fine) and The computer would not turn on. The light on the
motherboard was still lit (still getting power) but the power supply
fans would not start, nothing does anything. When I fooled around with
some stuff (i.e. turned the switch on the power supply from 1 to 0
then back to 1) the fans started to whir for a second without having
touched the soft power button in the front and then it sounded like a
small jet engine starting up and then dying.
So I figured, Hey, must be a dead power supply, so I ordered a brand
spanking new Thermaltake from new egg with a higher wattage (480).
Plugged it up and Voilla, computer still doesnt turn on...So does
anyone have any ideas?

Motherboard: ASUS A7V600
Processor: AMD ATHLON XP 2.01 GHZ
SATA 120GB harddrive, 80 GB IDE Harddrive.

The motherboard light is still on but powersupply doesnt turn on. The
only thing that comes to mind would be that the system panel connector
wires from the front ATX Power Switch/Soft are bad but I didn't touch
them from 5 days ago! and The computer has been working fine for 8
months now.

Okay, I'm rambling...who knows what's going on?
Thanks

As you say, check the case front power switch. Try to short the
two pins on the PANEL header together with a conductor like a
screwdriver tip. The switch is momentary contact, so you don't
have to leave the screwdriver touching, to keep the computer
powered up. Just a quick touch should start it.

System power up is gated by AGP_Warn, a circuit just below the
AGP slot, that checks for the illegal use of 3.3V video cards.
In fact, all it does, is check that pin A2 (that is on the solder
side of the card, on the end of the connector nearest the faceplate
of the video card) is grounded. If your video card isn't seated
properly, maybe that is preventing it from working.

On my motherboard "AC Power Loss Restart" seems to be supported
by BIOS code, rather than by hardware alone. If the computer is
switched off at the back, when I switch it on, it powers up for
a second, long enough for the BIOS to check that setting and
decide what the user wants, then shut off power again. Of course,
as soon as I push the button on the front, it starts.

HTH,
Paul