VX450W, have to hold power button to boot up, sometimes it doesn't boot at all.

[asuhdds]

Okay, so I bought a Dell Inspiron 518, then replaced the stock PSU with a VX450W Corsair and the 3450 GPU with a Radeon 4850. The problem is that, while before, when I pressed the power button with stock parts, the PC would boot up immediately. Now, when I press the power button, I have to hold the power button or press it multiple times to get it to start going. It's like the PC needs to get a running start in order to boot up. The fans start, then stop, then spin again and then it boots up normally. Sometimes it doesn't even boot however, and I have to just get lucky. When the computer does boot, it works perfectly fine, the PSU supplies power to the video card properly, even when stressed. It's just the bootup that's strange. Also, it seems to work better when I have the breaker switch off when the PC's off, then switch it on when I need to boot up. If I leave the breaker switch on after turning the PC off and leave it for several hours, the PC doesn't boot up as well if I press the power button (I have to press it 16 times or hold it for a long time).

 

When I replace the stock parts, it boots up normal by just pressing the button once.

 

I tried to short the power switch just now and it didn't boot up and did the stilted fan movement. The power switch is not the issue.

 

Is it a motherboard issue not sending a signal the PSU can read?

 

I wish I had another test system to see if the problem is with the PSU.

[RAM GUY]

I would recommend that you try the PSU functionality test from the following thread in our forum: http://www.asktheramguy.com/v3/showthread.php?t=63991. If the PSU powers on and stays on, then there is a possibility that your system is triggering the OCP/OVP (overcurrent and overvoltage protection) circuits on the PSU due to an out of spec signal from the motherboard. If this is the case then I would recommend testing the PSU in a different system to be sure. If the PSU is still not powering on properly then let us know and we will be happy to replace it! You may also want to check with Dell to see what type of PSUs would be compatible with your system, many OEMs will use proprietary PSUs specifically designed for your system. Our PSUs meet ATX 12v 2.01 or newer specifications.

[asuhdds]

Yes, I did use that paperclip test method and the PSU powered on.

 

What is "system triggering the OCP/OVP (overcurrent and overvoltage protection) circuits on the PSU due to an out of spec signal from the motherboard."?

[RAM GUY]

For instance if the board (or some other component) is asking for 14v from the 12v rail, the PSU will trip the OVP circuit and shut down in order to protect your board.

[asuhdds]

So if that's being triggered, is it a board issue or a PSU issue? I'm guessing a board issue?

[RAM GUY]

If the OVP is being triggered its due to a component requesting more voltage than it should, so the root of the problem would be with an out of spec component.