Motherboard running hot.

Dervious

Dervious

Dervious

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My PC just caught fire.

The ATX4P1 connector seems to be the culprit, as I`ve removed it, and the machine is running OK.

The machine was running fine, just checking email, when I heard a quiet "rustling" noise, roughly from the direction of the PC. The rustling got slightly louder, and then I saw a small wisp of smoke rising from the case. I got up and looked inside the machine (the side is usually off), and there were flames coming from an area near the graphics card, at the edge of the motherboard. I switched off at the mains (Windows was still running fine) and blew the flames out.

It appears that the ATX4P1 connector has melted and was the cause of the fire. I had connected this when I first put the system together, due to problems that I'd had with a previous Nvidia graphics card, rather than the usual reason of running more than one card.

Not impressed !
 
Hi, according to your mobo manual you only connect this when usin two or more GPU;s -

ATX4P1 (PCIe Power Connector)
The power connector provide auxiliary power to the onboard PCI Express x16 slots. When two or more
graphics cards are installed, we recommend that you connect the SATA power cable(s) from the power
supply to the ATX4P1 connector to ensure system stability.

It pays to read your mobo manual.
 
I did read that in the manual.

At the time I connected ATX4P1, I was having trouble with a troublesome GTX460. One of the recommendations that I read somewhere, was to connect this auxilliary power feed to help provide stability.

I didn't read anywhere that this should only be connected when more than one graphics card is installed.

On a more technical level, I would have thought that the connection would not come under any more "strain" (higher current delivery) with one card rather than two. Why would using this connection with just one card cause a fire ? And if it can cause a fire, where's the warning ?

As I understand it, this connection provides extra "power" to the PCI-E slots (extra current, should the installed graphics card(s) require it). It reduces the current demand that would otherwise be made of the motherboards supply circuitry.
 
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I know that it's not normally required, but I had issues with a GTX460. One of the suggestions to solve the problems I was having with that card was to connect the auxilliary power connector (for MBs without the connector, I seem to remember EVGA offering some sort of adapter for their cards). The idea was to supply the power more "directly" from the PSU, rather than via the motherboard's PCIe slot.

When I upgraded to a HD7950, I left the lead connected, and it's been fine for nearly 18 months. I think I`ve worked out what went wrong. There is obviously nothing actually wrong with my motherboard or my graphics card (they`ve worked perfectly for the past day or two since the incident). The problem is with the molex to SATA power adapter that I used. I understand that a graphics card can be supplied (or demand) upto about 6 amps through the PCIe slot. This is normally supplied through the motherboard itself. If the ATX4P1 connector is utilised, this power is taken directly from the power supply, rather than through the power rails of the main board. I think the problem lies in the fact that 6 amps is a fair bit of current for a SATA power connector (a hard drive or SSD would never draw anywhere near 6 amps). Over a period of time, my connector must have gradually deteriorated due to the heat generated by it's small contacts having to carry several amps. This would have generated heat, which slowly caused the connections and plastic to carbonise. Once the carbon reached a critical point, it would have started to conduct, and then rapidly heat up to the point that the plastic connector and insualtion on the cable caught fire.

I think Gigabyte need to know about this.
 
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