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PSU Power Supply Answered

I built a PSU bench power supply, but it isnt outputing the right voltages. It just out 5v for all lines(12v,5v). It has a purple wire that is said to be the stand-by, but the psu wont start unless it is connected to the 12v or 5v line. It also says that you have to have the brown sense wire attached to the 3v wire but this seems to do nothing. How can I make this thing output the right power(12v @ 22A, 5v @ 50A)?

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tylerb (author)2008-03-07

My PSU is broken, there must have been some wire in the case from stripping the wires. The Fuse is broken and a resistor exploded!!!. I'm just going to get a old one for like $5 bucks.

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tylerb (author)2008-03-05

I connected a 12v car light bulb to the 5v and GND to act like a resistor, but the PSU still wont start. I think it is broken and going to buy a used old one.

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Goodhart (author)tylerb2008-03-05

some of them are fused. But the fuse is a "last ditch resort" to save the unit, and they are normally soldered in .

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guyfrom7up (author)tylerb2008-03-05

mkae sure you're shorting the right wire, and usually it's to ground.

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tylerb (author)2008-03-05

I can output some serious power, but it isnt, becuase it wont start without the standy-by wire attached to the 5v wires. If I put a resistor on it it should start full power? what wires do i hook the resistor into?

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guyfrom7up (author)tylerb2008-03-04

looks pretty ugly, but it looks like it can give some serious power. Make sure the connectors have low enough resistance for enough amps to go where you need it

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tylerb (author)2008-03-04
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guyfrom7up (author)tylerb2008-03-04

I'd still put in the load resistor, for saftey, but that's just me. You probably can only get about half the power out of it, just a thing about desktop power supplies, but that one could be different.

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guyfrom7up (author)2008-03-04

I'm assuming you have a dell if you ground the gray wire (attach it to black and keep it there) the psu will turn on. It needs a load to work properly, and if you can't or dont know how to calculate the correct resistor (that was another form topic) then just attach a 10 ohm, 10 watt (I used an 8 ohm, 25 watt) to get everything working.

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