I was cleaning my PC and plugged the power cable back into the power supply. I heard a brief static or crackling sound, which I had occasionally noticed before, but when I pressed the power button the cable immediately began overheating and smoking near the PSU end. I shut the system off almost instantly, unplugged everything, and discarded the damaged cable. The PSU connector pins appear normal in the photos, and I have since bought a replacement cable. Is it safe to keep using this PSU, or should I replace it as a precaution? The system uses an RTX 4070 Ti Super, Ryzen 9 9950X3D, 32GB of DDR5 memory, an NVMe SSD, and an 850W 80+ Gold Gigabyte PSU that is less than a year old.
3 Answers
I would stop using the PSU until it has been properly checked. A wall-to-PSU cable is normally just a simple mains cable, so severe burning usually points to a bad connection, a damaged plug or socket, or a fault in the PSU inlet. Even if the computer still works, heat damage can affect the PSU connector and create a fire risk under load. Do not keep testing it with a replacement cable; contact the manufacturer or replace the unit, and inspect the wall outlet as well.
The cable rating probably was not the issue if it was a normal, undamaged mains lead intended for that region. An 850W PC does not require some special proprietary cable on the AC input. Replace the damaged cable, but also have the PSU checked or replace it—especially if there is discoloration, looseness, pitting, a burnt smell, or any melting around the inlet. A working idle system is not proof that it is safe at full load.
The most likely explanation is that the cable was not fully seated. A loose connection creates resistance at the contacts, which can generate enough heat to melt the connector or cable even though the PC is not drawing anything unusual. The cable should fit firmly with no visible gap, but because this one actually smoked, I would not assume the PSU is harmless just because the pins look okay.
That makes sense. I was worried because the replacement cable works and the PC is currently idling, but I will avoid stressing it until the PSU and outlet are checked.