Is the power supply unit functioning properly after you shorted it out?
Is the power supply unit functioning properly after you shorted it out?
So I made a mistake while putting together my rig (this is only my second build, 10 years after the first). I accidentally connected two fan wires that weren’t supposed to be linked. Even more surprising, I did this while the operating system was being installed.
There was a loud popping noise and everything stopped working, along with a faint burning smell. At least there was no smoke. 😂
After some research to fix the registry, I managed to restart the OS and finish the installation. All the rest of my software worked perfectly, and the case temperatures stayed normal.
Although the power supply seems to be functioning properly (it’s a Thermaltake Toughpower GF A3 750W, which is more than enough for my basic non-gaming use), I’m curious if this mistake might affect long-term reliability. Should I consider replacing it just to be safe? Any advice?
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If you heard a popping sound and a burning smell, it likely means something was damaged or died.
Antec NX410 case includes three fans that are daisy chained from the box and connected via a single SATA power cable. I accidentally disconnected them and connected one of the cables into a motherboard fan header. The issue arose when I attempted to link two unused 4-pin male connectors—one for the front fans and another for the rear fan, which was the only fan functioning at that time. (It was around 2 a.m., and I might have been too late.)
The following day, upon being more cautious, I found out that the rear fan cable I had connected to the motherboard wasn’t working at all; it was the one that needed reconnection to the front fans’ cable. It turned out the fans are not meant to connect to the motherboard directly, except for a single cable for RGB lighting, because they operate at full speed and continuously (this detail wasn’t mentioned in the product documentation).
The two spare unused 4-pin connectors seem to be present just in case I wanted to add more case fans later.
I'm more concerned about the motherboard than the PSU. Most ATX PSUs come with built-in short-circuit protection on all supply rails, which likely activated when you shorted the power supply. Keep in mind, the OCP won't activate until tens of amps are passing through the 12V rail.
As a general guideline, if your PSU can deliver 750W at 12V, that's about 62.5A. Adding a 10% to 20% buffer for overload gives you around 69 to 75A, which is sufficient to produce smoke.
If the fault current passed through the motherboard, it could have damaged components or melted traces. If only some wires were affected, look for melted insulation on fan cables or faulty fans. Replace any items that seem questionable.
Of course, you might be fortunate and avoid extra costs.
Do you know how to check if the motherboard is functioning properly? I'm worried about any damage that might affect unused ports or slots, like not planning to install a graphics card or more storage devices. The smell seemed stronger from the motherboard than the power supply unit. Overall, the system appears to be working well, running smoothly and quietly. The monitor displays temperatures that are consistently low, usually between mid 20s and low 40s.