Burnt PSU wires- Seasonic X850

So this weekend I've been seeing artifacts and random shutdowns. Finally I smelled a nice toasty burning plastic smell coming from my computer when my 7970 was under load. I check the video card to make sure everything was good- and it was fine. So I stress it again and the burning smell comes back. And turns out that the modular power supply cable was burnt! Two of the pins melted which probably was the cause of the shutdown problem.
I've had problems with the +12v on the 24 pin connector melting before, but this time it was the PCIe 4x2 8 pin connector.



So fortunately Seasonic is offering me a RMA, but do I need to get a non-modular power supply to avoid this problem again?

The first two things that come to mind - are you using the original wires that came with the X850? Other than that, the connection could have come loose and fried the socket/wires.

How long have you had your X850? I've had my P660 and P860 for a little under a year and no problems yet except a whine on the 860 that was resolved with an RMA.

To answer your other question, this problem doesn't seem common on modular PSUs. You probably just got a bad one.

mda said:

The first two things that come to mind - are you using the original wires that came with the X850? Other than that, the connection could have come loose and fried the socket/wires.

How long have you had your X850? I've had my P660 and P860 for a little under a year and no problems yet except a whine on the 860 that was resolved with an RMA.

To answer your other question, this problem doesn't seem common on modular PSUs. You probably just got a bad one.

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pretty much this ^

in my experience the main cause of burnt wires is either loose connections or shoddy workmanship, as long as you don't buy dirt cheep and secure your connections its not an issue.

You either A. made a mistake when plugging the wires in, or B. got unlucky.

In any case, just do the RMA. You will not find any high end power supplies that are non-modular.

I plug and unplug each connector 10 times before the first use because a lot of PSUs (multiple manufacturers) didn't work until I did that. I never saw that problem until about a year ago, but in the past I have seen loose molex plugs and crimps made with oxidized copper wires

Modular should be just as reliable as regular, but I wouldn't be surprised if some companies do a poor job designing or manufacturing the circuit board where all the modular sockets are attached. If the circuit board can flex or if the sockets aren't flush with the board, the soldering can crack when a cable is plugged in.

potatorage said:

Two of the pins melted which probably was the cause of the shutdown problem.
I've had problems with the +12v on the 24 pin connector melting before, but this time it was the PCIe 4x2 8 pin connector.

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1)Seeing this comment, i want to ask a similar question if you can help me:
My psu's 8-pin cable that powers my motherboard, has a small contact with the cpu's cooler.
The contact is at the metalic fins of the cooler. Is it possible this cable to melt down after long-term use or they can withstand heat?
2) And a question to potatorage: How long time were you using your psu untill these problems appeared? Did you stressed the psu with cpu overclocking, crossfire etc ?

Sith'ari said:

1)Seeing this comment, i want to ask a similar question if you can help me:
My psu's 8-pin cable that powers my motherboard, has a small contact with the cpu's cooler.
The contact is at the metalic fins of the cooler. Is it possible this cable to melt down after long-term use or they can withstand heat?
2) And a question to potatorage: How long time were you using your psu untill these problems appeared? Did you stressed the psu with cpu overclocking, crossfire etc ?

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1. If the contact is only minor and is not applying too much pressure either from the connector to the heatsink or the heatsink to the connector, that is fine. The jacket on the cables can melt, but not at normal operating temperatures of ANY part in a PC.

dandragonrage said:

1. If the contact is only minor and is not applying too much pressure either from the connector to the heatsink or the heatsink to the connector, that is fine. The jacket on the cables can melt, but not at normal operating temperatures of ANY part in a PC.

Click to expand...

Glad to hear that , because unfortunatelly the contact is unavoidable !!