Question About cable smoking after reconnecting my PSU to everything.
Question About cable smoking after reconnecting my PSU to everything.
Hello everyone. I'm just starting out with building PCs, so I took my old one apart to understand how it works. After turning it on, I saw smoke coming out of the case. When I opened it, the cable I linked to was glowing red hot and smoking. I'm looking for advice on what might be causing this issue.
All listed items are affected; one or more components are completely compromised.
Update your post with complete hardware details and operating system information.
PSU: make, model, wattage, age, condition.
Disk drives: make, model, capacity, usage level.
Two probable reasons:
1) The power supply failed to deliver adequate energy to the connected devices.
2) The cables and connections seem altered in ways that are both incorrect and poorly executed.
Disassemble the cable and discard it permanently—do not reuse it. Continued use risks severe system damage, potentially destroying your PC or causing a fire.
Locate the relevant documentation for each component used in your setup.
Starting with the motherboard.
Ensure you use original cables without any modifications, splices, adapters, or converters unless they are explicitly designed for this purpose.
For instance, if a modular PSU is part of the build, only the cables supplied with that PSU should be used in their unmodified state.
Halt your current work and seek assistance from an experienced family member or friend.
You might not have the same luck next time.
I had it constructed by a local firm some time ago, and it functioned properly until I made some changes. The whole system is roughly 5 or 6 years old, with all parts included.
Power Supply: ThermalTake Smart 650W – approximately 5 or 6 years old. Appeared to be in decent shape.
Mainboard: GigaByte GA-Z87X-D3H
Graphics: Zotac GeForce GTX 760
RAM: 2 Corsair xms3 8GB
Storage: 1 750GB HDD
DVD Drive: Uncertain
Just to confirm, I’m not completely new to these things—I’ve been studying this for about a year in school. I’m about to take my A+.
I understand, I'm really puzzled. I've inspected the cables connected to my motherboard and hard drive, and everything looks fine. The Molex cable itself seems unaffected, but the one attached to it is the one that's glowing. I don't have much experience with this specific cable.
It requires significant energy to make a cable emit a red-hot glow and damage the insulation. A practical test involves disconnecting a car battery using a thin insulated copper wire, such as 20awg. Be careful—do NOT attempt this at home!
This action likely caused a short circuit on the +12V rail of the Molex connector (yellow wire), either to ground or possibly to the +5V rail (red wire). Such a mistake could occur if the Molex cable was inserted incorrectly.
Molex connectors are designed to avoid reverse connections, but strong enough force can force them back together, leading to serious consequences.
If some insulation remains, inspect whether the red wire on one side of the connector is linked to a yellow wire on the other side.
The 12V rail in most ATX power supplies ranges from 20A (240W) to 125A (1500W), which is sufficient to melt cables before overcurrent protection activates.
Examine what is connected at the other end of the melted plugged cable. The component there is likely damaged.
It might also be wise to replace the power supply. Because a cable outside the PSU has melted, it’s possible another cable inside the PSU has been affected, making the unit unsafe. Avoid risking devices connected to AC mains.
Electricity behaves differently. If the mess on the floor originates from the power supply, the issue likely lies to the left in the image. It might be inside the connector or directly to the right of that mess.