Dead ATX power supply, please help.

[ashayalmighty]

Antec VP500PC Made by CWT on GPA platform.
No UPS

• Was using the computer normally.

• Sudden blackout!

• Hadn't turn off the switches.

• The electricity comes back and I hear some sort of spark.

• The PC wouldn't boot up, not response at all!

I could see a burnt inductor from the PSU's meshed back.
Please help me find the rating of this toroid inductor. The one next to the ceramic fuse. I am trying to fix the PSU, any schematic would help as well.
(The core had white paint before it burnt, also had so much glue around it that had turned brown form white. )

[ashayalmighty]

Re: Dead ATX power supply, please help.

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[R_J]

Re: Dead ATX power supply, please help.

Is the coil connected where the a/c line comes in? if it is it is not that critical and you could find some similar coated wire and rewind it, or find a similar coil from another power supply. If it IS connected directly to the a/c line you can replace it with a jumper wire to test if the power supply works.
Post of picture of the trace side of the board to show how it is connected.

[ashayalmighty]

Re: Dead ATX power supply, please help.

I've attached the images.
Video link.
Thanks.

[R_J]

Re: Dead ATX power supply, please help.

It is not critical, you can install a wire in place of the coil if you like. Or find some coated wire and rewind the coil.

[eccerr0r]

Re: Dead ATX power supply, please help.

nice, inductor fried itself to protect the fuse, that's a new one. Usually transistors do that.

Then again, likely there are fried transistors here after all is done and through...

[ashayalmighty]

Re: Dead ATX power supply, please help.

It is not critical, you can install a wire in place of the coil if you like. Or find some coated wire and rewind the coil.

The inductor core is stripped off of the paint, do I need to repaint it or just skip it and directly rewind the core?

[ashayalmighty]

Re: Dead ATX power supply, please help.

it is not critical, you can install a wire in place of the coil if you like. Or find some coated wire and rewind the coil.

nice, inductor fried itself to protect the fuse, that's a new one. Usually transistors do that.

Then again, likely there are fried transistors here after all is done and through...

Is the any way to check the transistors and other components using a multimeter?

[R_J]

Re: Dead ATX power supply, please help.

The inductor core is stripped off of the paint, do I need to repaint it or just skip it and directly rewind the core?

You can just rewind it, You must use coated wire not bare copper wire. The paint color is only to indicate the core material etc.
If you do replace the coil, place some insulated material between the coil an the fuse to prevent them from touching and shorting.

[ashayalmighty]

Re: Dead ATX power supply, please help.

You can just rewind it, You must use coated wire not bare copper wire. The paint color is only to indicate the core material etc.

Okay, thanks.
What gauge wire should I use though?

[R_J]

Re: Dead ATX power supply, please help.

Is the any way to check the transistors and other components using a multimeter?

Check that the bridge rectifier is not shorted, and also check if the main switching mosfets are not shorted.

If the coil was still making connection in the circuit the power supply should have still worked even though the coil was burnt. It was likely running hot for a long time. Were the connections on the coil loose or was the coil wire open circuit?
It should be safe to plug in and check if you have standby voltage. I would also check the board for poor solder connections

[ashayalmighty]

Re: Dead ATX power supply, please help.

Check that the bridge rectifier is not shorted, and also check if the main switching mosfets are not shorted.

If the coil was still making connection in the circuit the power supply should have still worked even though the coil was burnt. It was likely running hot for a long time. Were the connections on the coil loose or was the coil wire open circuit?
It should be safe to plug in and check if you have standby voltage. I would also check the board for poor solder connections

The coil was open circuited.
I will check for any poor soldering connections.
I don't have any idea what stand by voltage is, I'd like to know more, is it the thing that's responsible for sleep and hibernation.

[R_J]

Re: Dead ATX power supply, please help.

If the coil was open circuit, you can just use a short piece of wire to replace it for now, If you want to rewind the coil, use the same gauge wire that was on it, or something close. The coil is only there to prevent some of the power supplies switching noise from going back onto the power line. For the voltages look at a atx power supply plug pinout diagram.

[ashayalmighty]

Re: Dead ATX power supply, please help.

Thank you very much every one!
I have successfully winded and soldered the coil, it was a week ago and everything has been working as good as new!
The only thing that didn't work is the hot glue that I used to hold the coil in place, it melted away, what kind of hot glue do the factories use? Anyone has any idea?

Thanks for the help!

[R_J]

Re: Dead ATX power supply, please help.

You can just use some rtv silicon to secure it, but I would not be to concerned about its mounting since its not getting shipped around the country etc.

[eccerr0r]

Re: Dead ATX power supply, please help.

Then again this is not a good sign that the coil is getting hot... is it melting under no/low load?

[jonnyGURU]

Re: Dead ATX power supply, please help.

Then again this is not a good sign that the coil is getting hot... is it melting under no/low load?

This.

I've never had a coil just burst into flame for no reason.

[PeteS in CA]

Re: Dead ATX power supply, please help.

Then again this is not a good sign that the coil is getting hot... is it melting under no/low load?

The picture in the OP suggests that the inductor is a differential mode inductor, possibly wound on Micrometals -52 material. If that is correct (there is RTV that partly blocks the view) and if the original inductor over-heated, that could have affected the core's magnetic properties, causing the high temperature ashayalmighty mentioned.

[ashayalmighty]

Re: Dead ATX power supply, please help.

Then again this is not a good sign that the coil is getting hot... is it melting under no/low load?

I don't actually know how much power the computer is actually using, but the computer is turned on (not idling) for at least 6-8 hours daily 7 days a week.
Mostly web browsing and sometimes light gaming.
And it's been at least a week of the aforementioned usage.

The glue stick I used was EVA, does that make any difference?

[ashayalmighty]

Re: Dead ATX power supply, please help.

This.

I've never had a coil just burst into flame for no reason.

The coil did not burn when the computer was turned on (electricity was cut-off due to blackout), the computer was off but plugged in to the socket and when the light came back I heard some sort of spark and then the PC wouldn't turn on.
Also I am not claiming that coils burn without any cause, I am saying that it was mostly likely a power surge.