The PSU cables ignited.
The PSU cables ignited.
It seems the issue might be related to the cables and connectors overheating and damaging themselves. Overcurrent could stem from intentional overloads or unintentional shorts, making it clear or unclear depending on the cause.
Overclocking isn't really worth it unless you're using a much stronger processor than a regular home build. It's better to prioritize cooling performance rather than just aesthetics. How much voltage were you using? It's unlikely anything over 1.4 volts per core will help, since these chips are tough to cool at higher voltages.
Oh no! Did you accidentally use a non-Corsair extension cable? That’s definitely a risky move...
If you can remove the GPU waterblock and share some images of both sides of the graphics card board, it’s likely there’s a damaged component like a blown MOSFET or resistor that caused damage. The burn mark would probably be clear in a specific area, possibly under thermal pads or heatsinks. It might be visible from both sides if it penetrated straight through. It’s unlikely to be a capacitor. If the main power capacitor in a PSU failed, it would probably shut down without any harm to the rest of the system—no melted wires like this. The overheating cables likely caught fire at the connector due to excessive current. I don’t think it was a power supply failure; instead, a component probably failed first, leading to a short that overloaded the cables. The RM1000x is a single-rail PSU designed to handle high current on one cable before protection circuits activate. It can deliver up to 83A on a 12V rail, but real-world PSUs often exceed this rating before tripping. Since it’s a single-rail unit, it can’t tell the difference between drawing power across the whole system or just one cable. It would have assumed normal operation, like “90A is fine.” However, only a few cables would be affected. PSUs do have short-circuit detection, but if resistance is high enough they might not trip. Then overload protection (OPC/OPP) would engage, but with a 1000W unit that’s a significant threshold. The brand of extension cables probably doesn’t matter because all PSUs use the same wiring. The cables connected directly to the PSU must match that model, though they’re wired differently. @jonnyGURU this could be relevant for you
The entire setup seems to have experienced a minor overheating issue rather than a major electrical surge, which would have caused immediate component failure. Examining the second and third images suggests the extension cables are melting, but not the ones connected to the PSU. The melting appears to begin right where the extension plugs into the standard cables, indicating possible overheating and subsequent fire at the fusion point. I own an RM850x and the manual recommends only using Corsair extension cables, which I followed. Using non-compatible cables might be the root cause.
There are variations in the cables connecting the modular power supply and extension wires. Extension cords, which OP utilized, are compatible with any power supply due to their use of standard wiring and connectors. These power supply cables are designed to interface with components, whereas the original PSU cables plug directly into the components. The standardization of PSU cable ends ensures compatibility with PCs. Cables that connect directly to the power supply follow unique wiring patterns not shared across different models. In modular setups, variations like 5V versus 12V wires can cause issues if mismatched. For direct connections, it's essential to use cables specifically intended for the power supply model. The connectors can become weak points, leading to poor contact or pin ratings that don't match the wire capacity. Corsair and Antec cables both employ 16AWG wiring for their extension lines, as confirmed by Antec's website. It's conceivable that the wires themselves can handle more current than the connectors allow. The Molex Minifit Jr connector supports up to 9A per pin, and overloads often fail at the connector. While extension cables didn't seem to be the root cause, they might have contributed if a surge occurred elsewhere. Overall, the cables tended to melt gradually rather than ignite, suggesting a significant difference in insulation quality. If genuine counterfeit cables caused the problem, it would likely raise concerns beyond just the melting issue.