Seems that yet another miner has had a nuclear meltdown in his power distribution system. The connections are completely melted but escaped a flameout that could have been even worse.
The problem is that many use poor quality power supplies and run them beyond their rated capacity. Then some the splitters to connect more video cards. The results are obvious. That is why the cables melted. By good fortune the connectors did not catch fire readily thanks to retardants being used.
Most likely the power problem also destroyed a video card or two. That is why there are so many posts here on power supplies and safety.
Here at the studio we use elite Corsair power supplies so that they are safe as the machines they power are expensive. Corsair have a deserved reputation for quality that is exemplary in the industry. Even the venerable TX850V2 still is a said power supply that still works fine. It has simply been obsoleted by more recent modular cable based models that are also more efficient.
At present the AX1600i is the best model PSU out there and it handles the gaming box fine. At 80 plus titanium and 94% efficient there is nothing out there that can compete. The machine barely used 400W so the PSU is excessive but the efficiency is ideal.
Many question the 500W PSU with a 400W load and then the load falls to 200W and the PSU trips. Pushing a low end PSU that hard is not going to get very good results.
Here at Hardcore Games a 650W PSU is now our minimum so that a discrete card can be installed. The GTX 1060 we have can be used for video transcoding which does not use a lot of power and machine can be configured for long term encoding tasks. The RM650 has been a solid performer for more modest tasks.
Over in China mining as a share of the sector is now zero. The reason is that the nation has a power shortages galore and can ill afford to waste power on mining bitcoin etc. China needs to build maybe more nuclear plants but they take several years to build.
The US and Canada have seen significant increases in mining activity suggesting Chinese machines are being shipped over in volume. Canada is energy rich but mining is very demanding.