Put in new VX450W, Computer still won't switch on...

Hey guys,

After replacing the power supply on my computer, the computer still will not turn on.

SPECS:
Corsair VX450W
Asus P5GD1 -
P4 540 3.2GHz HT 1MB L2 cache
2 * 512MB DDR PC3200
X1950pro 256Mb
250GB SATA Hard drive 7200RPM
1 DVD drive
1 DVD-RW / CD-RW drive
memory card port thingy

I'm really at a loss at what to do. I don't think the PSU was the problem, in which case I bought an excellent new PSU for no reason xD, but perhaps the button to turn on my computer is faulty? But why would that randomly cause the computer to turn off, and not turn back on, after being absolutely fine for years?

Any advice? Nothing turns on still, only the LED on the mobo is on, whenever the power switch is flicked on the PSU. Anyway to manually turn the computer on without a button to check?

EDIT: I read that I can short out the two pins, that complete the circuit to turn the computer on, but i have no idea which ones they are. I can't trace them back from the button.

Thanks,

Dave

It should be marked on the motherboard normally.

If you can't find it, look at your motherboard's manual, short the two pin which says PWR BTN (Power button)

Quote:

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Originally Posted by arthurleung

It should be marked on the motherboard normally.

If you can't find it, look at your motherboard's manual, short the two pin which says PWR BTN (Power button)

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I don't have the motherboard manual. I can't find any pins marked with power, I can find only one bit marked pwr sw, but it's not pins, just a random bit of the tracks.

Dave

Its marked in very small writting on the motherboard, just look where a large group of headers are and read the writing that surrounds it. Your on the right track if you see reset sw, hdd led.

Quote:

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Originally Posted by digit

Its marked in very small writting on the motherboard, just look where a large group of headers are and read the writing that surrounds it. Your on the right track if you see reset sw, hdd led.

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Cannot find it, there was a connector leading to the power button and LEDs originally there, that I pulled out together, but i cannot remember the order in which they were plugged in.

At the pins that the connectors were originally plugged in, it is marked chasis. Beside those pins, is a bit that is marked panel, that has IDE_LED, PWR SW, and RESET marked, and the manual (I found online) points this out as well, but there are no pins here (as the manual suggests), and I know for a fact, that the power button was connected in the part marked chasis when it was working...

Any ideas?

Thanks

You tried shorting the pins to see if that results in a power on? You could in theory short all pins and you'd eventually get the right ones :) Its possible I guess the wires to the terminals on your power button might have a bit of a dodgy connection or come off. If possible check to see if the wires lead directly to the power button and that they are connected, perhaps fiddle with them a bit just to make sure they are connected.

Quote:

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Originally Posted by digit

You tried shorting the pins to see if that results in a power on? You could in theory short all pins and you'd eventually get the right ones :) Its possible I guess the wires to the terminals on your power button might have a bit of a dodgy connection or come off. If possible check to see if the wires lead directly to the power button and that they are connected, perhaps fiddle with them a bit just to make sure they are connected.

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I've tried to short out all the combinations of the pins present. I get a few sparks when i short out a specific pin, and when doing the so the LED on the motherboard turns off, until you stop shorting it.

I'm at a loss at what to do :(

EDIT: I can't access the button on the case, very difficult, and i can't remove it, to take a closer look

There is a short somewhere on the mobo i think and every now and then it trips.

Take it ALL out and rebuild it.

Have you ensured that all standoff points underneath the motherboard are in the correct places? It is essential they are underneath the correct holes. Otherwise if not it can lead to a short which Blitzen mentioned above :(

Hey guys, thanks for all the replies.

I gave the computer to my mum, who said she would get her computer tech at work to look at it.

The thing is, that the computer had not been moved at all, nothing had been changed within the last week of it dying, and it did not exhibit any weird signs at all, before it suddenly switched off when I was loading up counter-strike: source. I can understand if I had moved it arround, or had been doing any work on it, but the computer was entirely stationary :/

I really wish, I had taken out the motherboard to have a look, after hearing it could have been a grounding issue, but alas I was desperate to get it up and running properly again, and I have exams and can't really afford the hassle of messing about all day with it xD

Thanks once again guys ^_^

EDIT: A little thin metal bit fell out (it looks like some sort of clip) when I was installing the new PSU, any idea what it might have been?

Dave