PSU cables caught fire

[ArmouryComputers]

Hello Everyone, so recently I built my dream watercooled PC with the following specs 

 

intel 19-12900K (NEW)

ROG Maximus Z690 (NEW)

32GB Dominator DDR5 5600MHz (NEW)

RM1000x Corsair PSU (1 Year Old)

2TB PCIe4.0 WD black m.2 (NEW)

Gigabyte Aorus 3090 Xtreme Waterforce

 

but after around one week of usage, I left the room for 15 minutes and the computer PSU wires caught fire, I live on campus so I went out of the building as soon as the fire alarm went off so the fire could have been going on for several minutes, and in the time, 3 cables caught the fire but it’s hard to understand which one set it off, GPU power cables, CPU power cables and RGB controller cables all caught fire, see the pictures attached, if anyone can help me as I’m struggling to understand where it would’ve come from and how I can prevent it next time

Also bare in mind that there was a bang sort of sound 30 minutes before this all happened, I thought it was the pipes that blew and spewed the coolant everywhere but there was no sign, so if I’m correct, it could have been a capacitor blow but I’m not sure.

 

the security team that went in the room to rip the plugs off the wall when it was on fire told me that the computer was still running and wasn’t off because the computer can’t tell if the wires are on fire obviously.

 

but like I said, if anyone can help me, I’ll be extremely grateful, in the mean time to make sure that the CPU, Ram and SSD are ok, I’ve ordered a new Motherboard and a new PSU so will test them as soon as they arrive.

 

the black cable to white power cable is for the GPU, the black cables with copper exposed and one of the copper wires melted off is for the CPU and the RGB controller cable is stuck to the CPU cable

 

[Spotty]

Yikes, that looks like some pretty nasty damage.

 

With the CPU cable that melted was that plugged directly in to the motherboard or was that tucked down the bottom of the case with the other cables? Plugged in to an extension cable?

I'm guessing all the PSU cables were tucked down the bottom of the case with the extension cables going to the components. Makes it a little trickier to see where exactly it failed. Looking at the pics of the PCIe power cables melting it could be where it started as melting at the connectors between the extension cable and PSU cables is where I would expect to see and the other cables were possibly just in close contact with them tucked in the bottom of the case.

 

When you left the PC was it running a load at the time? Playing a game, rendering, mining, etc? Something that would put a high power load on the PC? Or was it just idle on the desktop?

 

Out of curiosity what brand cable extensions were those?

[Somerandomtechyboi]

Did you go overloading the connectors with too much current going through them? Usually that only happens if you split an 8 pin into 2 8 pin or too many fans for 1 cable

 

I would think cables catching on fire would happen to me first since after all my psu and cables is of dubious quality (also over a decade old) and i overcurrent them anyway by hooking up a 72w tec on molexes that arent even supposed to draw 6a on 12v xD

 

17 minutes ago, ArmouryComputers said:

Also bare in mind that there was a bang sort of sound 30 minutes before this all happened, I thought it was the pipes that blew and spewed the coolant everywhere but there was no sign, so if I’m correct, it could have been a capacitor blow but I’m not sure.

Did you see any smoke? If the psu starts smoking swap it out right away cause if it malfunctions and dies it could take out other parts too

 

If its this high end of a build id assume you wouldnt be stupid enough to cheap out on cables, adapters, hubs, etc. Right?

[Spotty]

21 minutes ago, ArmouryComputers said:

Also bare in mind that there was a bang sort of sound 30 minutes before this all happened, I thought it was the pipes that blew and spewed the coolant everywhere but there was no sign, so if I’m correct, it could have been a capacitor blow but I’m not sure.

It could have been something on one of the PC components (such as the graphics card or motherboard) blowing and causing a short/open connection which drew a lot of current as it shorted causing the cables to melt. I'd start by removing the waterblock on the GPU and inspecting the card for any damage.

[ArmouryComputers]

10 minutes ago, Spotty said:

Yikes, that looks like some pretty nasty damage.

 

With the CPU cable that melted was that plugged directly in to the motherboard or was that tucked down the bottom of the case with the other cables? Plugged in to an extension cable?

I'm guessing all the PSU cables were tucked down the bottom of the case with the extension cables going to the components. Makes it a little trickier to see where exactly it failed. Looking at the pics of the PCIe power cables melting it could be where it started as melting at the connectors between the extension cable and PSU cables is where I would expect to see and the other cables were possibly just in close contact with them tucked in the bottom of the case.

 

When you left the PC was it running a load at the time? Playing a game, rendering, mining, etc? Something that would put a high power load on the PC? Or was it just idle on the desktop?

 

Out of curiosity what brand cable extensions were those?

Yes the CPU cable was straight from the PSU to the motherboard, but there was a bit of tension on the cable as the distance the cable needed to go was slightly long and ended up having to bend the cable hard to get it in but it was running fine under all stress tests, I used the system for heavy gaming and everything, but yes the cpu cable and the GPU cable were all tucked under, in the PSU shroud.

 

when I left the PC it wasn’t under load, maximum of 5% CPU load and 2% GPU load as there were a few task running but not enough to overheat

[OhioYJ]

7 minutes ago, ArmouryComputers said:

Yes the CPU cable was straight from the PSU to the motherboard,

Yes but what about extension cables? From your pictures it appears you had extensions in the mix. It looks like a mix of black cables (not the burnt ones), white cables, and maybe even some flat ribbon style ones?

 

The extension cable while cheaper and easier, are generally frowned upon, as they can cause problems, and do things like this.

 

Either way, just glad you caught it before anything really bad happened. That's the most important part. 

[ArmouryComputers]

11 minutes ago, Somerandomtechyboi said:

Did you go overloading the connectors with too much current going through them? Usually that only happens if you split an 8 pin into 2 8 pin or too many fans for 1 cable

 

I would think cables catching on fire would happen to me first since after all my psu and cables is of dubious quality (also over a decade old) and i overcurrent them anyway by hooking up a 72w tec on molexes that arent even supposed to draw 6a on 12v xD

 

Did you see any smoke? If the psu starts smoking swap it out right away cause if it malfunctions and dies it could take out other parts too

 

If its this high end of a build id assume you wouldnt be stupid enough to cheap out on cables, adapters, hubs, etc. Right?

No i didn’t overload them, the GPU cables were running from two PCIe power cables from the PSU the PSU cables which go from 8 pins and then split to another 6 pin, so I needed two 8 pin connections, and no there was no smoke when I heard the sound, and no all the PSU cables were from Antec so were premium 

[ArmouryComputers]

13 minutes ago, Spotty said:

It could have been something on one of the PC components (such as the graphics card or motherboard) blowing and causing a short/open connection which drew a lot of current as it shorted causing the cables to melt. I'd start by removing the waterblock on the GPU and inspecting the card for any damage.

Yes I’ll be doing that next to check, I’ll get the motherboard, PSU and GPU checked for the capacitors

[Somerandomtechyboi]

2 minutes ago, ArmouryComputers said:

No i didn’t overload them, the GPU cables were running from two PCIe power cables from the PSU the PSU cables which go from 8 pins and then split to another 6 pin, so I needed two 8 pin connections, and no there was no smoke when I heard the sound, and no all the PSU cables were from Antec so were premium 

In that case the obvious cause was a short, but where tho? It could be a part like the rgb/fan hub just randomly shorting out or the cables just decided to short themselves out

[ArmouryComputers]

3 minutes ago, OhioYJ said:

Yes but what about extension cables? From your pictures it appears you had extensions in the mix. It looks like a mix of black cables (not the burnt ones), white cables, and maybe even some flat ribbon style ones?

 

The extension cable while cheaper and easier, are generally frowned upon, as they can cause problems, and do things like this.

 

Either way, just glad you caught it before anything really bad happened. That's the most important part. 

The only extension cables were used on the 24 pin which was completely fine and the GPU cable which is the one that burned down at the connection point , but bare in mind that the point of the cpu cable that was burned, GPU cables connection point and the RGB controller cable all burned at the same place so whichever one that started it off is hard to understand 

[ArmouryComputers]

1 minute ago, Somerandomtechyboi said:

In that case the obvious cause was a short, but where tho? It could be a part like the rgb/fan hub just randomly shorting out or the cables just decided to short themselves out

I see, what do you recommend I do next? So far all I can think of is sending the PSU to Corsair to be inspected, getting the motherboard opened up and checked and sending the GPU to gigabyte repairs which is around the corner from me to be inspected for damage inside

[Somerandomtechyboi]

5 minutes ago, ArmouryComputers said:

I see, what do you recommend I do next? So far all I can think of is sending the PSU to Corsair to be inspected, getting the motherboard opened up and checked and sending the GPU to gigabyte repairs which is around the corner from me to be inspected for damage inside

Honestly not sure, if its cables and connectors themselves shorting out and burning themselves is pretty straightforward but overcurrent ranges from deliberate overcurrent like me or something shorting out aka obvious to not obvious cause

[ArmouryComputers]

4 minutes ago, Somerandomtechyboi said:

Honestly not sure, if its cables and connectors themselves shorting out and burning themselves is pretty straightforward but overcurrent ranges from deliberate overcurrent like me or something shorting out aka obvious to not obvious cause

The only overclocking I used was intel XTU but I didn’t touch current, only messed with the frequency and voltage offset values

[Guest]

Bare wires and melted insulation looks bad, but the fire started at the connector that is melted the most.

[Somerandomtechyboi]

2 minutes ago, ArmouryComputers said:

The only overclocking I used was intel XTU but I didn’t touch current, only messed with the frequency and voltage offset values

Cpu overclock is pointless anyways, youll need something much beefier than a beefy normie custom loop, let alone a loop thats focused on aesthetics, more like big car radiator levels of cooling. Though how high of a volt did you run? I doubt anything over 1.4v all core cause these cpus are extremely hard to cool when overclocked

[PDifolco]

Urggh... Nasty

 

Did you unfortunately use non-Corsair extension cables ? This is a sure recipe for disaster...

 

[Spotty]

If you can dismantle the GPU waterblock and post a couple of pictures of both sides of the graphics card PCB. Would not surprise me if there's a blown mosfet or resistor somewhere that has burnt a hole in the board. Should be a pretty obvious burn mark in a specific spot on the board, might be under thermal pads/heatsinks though. Might be visible from both sides of the board if it burned straight through.

 

41 minutes ago, ArmouryComputers said:

Yes I’ll be doing that next to check, I’ll get the motherboard, PSU and GPU checked for the capacitors

Probably won't be a capacitor. If the primary capacitor in a PSU failed it would likely just switch off without any damage like this to the rest of the system, you wouldn't see melted cables like that. Those cables almost certainly melted at the connector because there was too much current going through them. I don't think it was a failure of the power supply, I suspect that a component (likely graphics card) failed first and a short caused the cables to overload and melt. The RM1000x is a single rail PSU and can deliver a very high current over a single cable before protections will trigger shutting it down. The RM1000x is rated for 83A on 12V rail, though in reality PSUs are capable of providing more than what they're rated for before the protections trip. Since it's a single rail power supply the PSU can't differentiate between power being drawn across the entire system or just one cable - it would have been like "The system is drawing 90A? OK I can do that!" without realising that 90A was going down only one or two PCIe cables. PSUs do have SCP to detect shorts but if there's enough resistance they don't always trip and then you're relying on OCP/OPP to kick in but with a 1000W power supply that's a pretty high tripping point, could be as high as around 110A over 12V before it trips.

 

5 minutes ago, PDifolco said:

Did you unfortunately use non-Corsair extension cables ? This is a sure recipe for disaster...

If it was a short somewhere else in the system I don't think it would have mattered what brand the extension cables were. Extension cables are wired the same across all PSUs so it doesn't matter if you use a different brand extension cables. The cables that plug directly in to the PSU must be compatible with that model though as they're wired differently.

 

 

@jonnyGURU this will probably interest you

[PDifolco]

15 minutes ago, Spotty said:

 

If it was a short somewhere else in the system I don't think it would have mattered what brand the extension cables were. Extension cables are wired the same across all PSUs so it doesn't matter if you use a different brand extension cables. The cables that plug directly in to the PSU must be compatible with that model though as they're wired differently.

 

 

The whole system don't look like it has undergone a big electrical surge (because then the inside components would have been dead instantly), but more like a fire caused by cable melting. Looking at the 2nd and 3rd pics it looks like the extension cables melted but not the cables plugged in the PSU, melting started just where the extension cables are plugged to the vanilla ones, so it's possible that the extension cables overheat then caught fire where they reached fusion temp  ...

I do have a RM850x and it's specified that you need to only use Corsair extension cables (which I did, and nothing caught fire yet  ), using not fully compatible cables could be the cause.

[Spotty]

1 minute ago, PDifolco said:

I do have a RM850x and it's specified that you need to only use Corsair extension cables (which I did, and nothing caught fire yet  ), using not fully compatible cables could be the cause.

There's a difference between the cables that attach to the modular power supply and extension cables. Extension cables, which is what OP used here, can fit on to any power supply because they use the standard wiring and connectors used by components since the end of the PSU cables that normally plug in to the components are instead plugged in to the extension cables. The end of the PSU cables are all standardised so that they work with the PC.

The cables that plug directly in to the power supply use different wiring that is not compatible across different power supplies. Depending on the layout of the modular panel some PSUs might have a 5V wire where another PSU has a 12V wire - if you mix those cables up that's when you have problems. For the cables that plug directly in to the power supply you must use cables that are designed to be used with that model of power supply.

 

4 minutes ago, PDifolco said:

Looking at the 2nd and 3rd pics it looks like the extension cables melted but not the cables plugged in the PSU, melting started just where the extension cables are plugged to the vanilla ones, so it's possible that the extension cables overheat then caught fire where they reached fusion temp 

Yep. With cables the connector is a weak point in the chain as you can have poor contact between the two connectors that are mated together or the connector/pins could be rated for a lower current than what the wires themselves are rated for. Corsair cables use 16AWG wire to the first PCIe connector and Antecs website says they use 16AWG for the wires in their extension cables as well. It's possible the wires can handle a higher current than what the pins/connector can. The Molex Minifit Jr connector used for PCIe/CPU/motherboard connectors is rated for max 9A per pin. When the cable is overloaded with too much current the first thing that will fail is typically at the connector. The cable failed at that point because it was where it is weakest, but I don't think it's the extension cables which caused the failure in the first place. I think there was a failure elsewhere that caused a current spike which caused the cables to melt and the connector between the PSU cables and extension cables just happened to be the weakest point where they melted first. Having extension cables definitely didn't help but it probably would have melted the PSU cables even if they didn't use extension cables at all.

I'm sure the Antec extension cables are comparable to other brands of extension cables, including Corsair or likes of Cablemod etc. It's also worth noting that looking at those pictures it seems that the cables failed safely - melting instead of igniting. Might seem like a minor nitpick but there's a big difference between the sheathing on a cable melting and catching fire. If it was really bad knockoff cables and the cables caught fire then OP would likely be asking us why their apartment burned down instead of why their cables melted.

[ArmouryComputers]

3 hours ago, Somerandomtechyboi said:

Cpu overclock is pointless anyways, youll need something much beefier than a beefy normie custom loop, let alone a loop thats focused on aesthetics, more like big car radiator levels of cooling. Though how high of a volt did you run? I doubt anything over 1.4v all core cause these cpus are extremely hard to cool when overclocked

Yes it wasn’t any more than 1.4 V so the overclock wouldn’t have been a problem 

[ArmouryComputers]

3 hours ago, PDifolco said:

 

The whole system don't look like it has undergone a big electrical surge (because then the inside components would have been dead instantly), but more like a fire caused by cable melting. Looking at the 2nd and 3rd pics it looks like the extension cables melted but not the cables plugged in the PSU, melting started just where the extension cables are plugged to the vanilla ones, so it's possible that the extension cables overheat then caught fire where they reached fusion temp  ...

I do have a RM850x and it's specified that you need to only use Corsair extension cables (which I did, and nothing caught fire yet  ), using not fully compatible cables could be the cause.

I see, I have ordered an EVGA supernova 1300W PSU this time, but like you said, ill buy their own extensions cables this time

[Somerandomtechyboi]

7 minutes ago, ArmouryComputers said:

Yes it wasn’t any more than 1.4 V so the overclock wouldn’t have been a problem 

In that case unless you only have 4 pins plugged in then no way the eps connector caught fire

[--SID--]

3 minutes ago, ArmouryComputers said:

I see, I have ordered an EVGA supernova 1300W PSU this time, but like you said, ill buy their own extensions cables this time

Don't use extension on a fully modular PSU. Use replacement cables only.

[ArmouryComputers]

3 minutes ago, Somerandomtechyboi said:

In that case unless you only have 4 pins plugged in then no way the eps connector caught fire

No, all 8 pins were connected to the CPU 

[ArmouryComputers]

1 minute ago, --SID-- said:

Don't use extension on a fully modular PSU. Use replacement cables only.

What do you mean by replacement cables sorry? I’m sure if the extensions are supplied by the manufacturer then they should be ok right?