Question Is my PSU still ok after I shorted it out?

[zenrunner92]

Ok, so I goofed while assembling my rig (be kind, this is only my 2nd build, 10 years after the first one) I goofed and tried to connect two case fan wires that were not meant to be connected. Even stupider, I did this while the OS was being installed.

There was a popping sound and everything shut down and a slight burning smell. No smoke, at least. 😂

However, I was able to power it back on but kept getting the "Windows installation cannot continue" popup. After a bit of googling to find a regedit fix, was able to complete the OS install. Installed rest of my software, no problems, works fine, case temps perfect.

So while the PSU appears to be working fine (it's a Thermaltake Toughpower GF A3 750W, way overkill for my modest non-gaming usage) I am wondering if there could be any long-term reliability issues as a result of my goof, or whether PSUs generally are designed to shrug off such things without breaking a sweat, or if I should exchange it for a new one just to be safe.

Thoughts?

 

[SkyNetRising]

tried to connect two case fan wires that were not meant to be connected.
I am wondering if there could be any long-term reliability issues as a result of my goof

We have no idea, where and how you were connecting those fans.
Provide photos.
(upload to imgur.com and post link)

If there was a popping sound and burning smell, then probably something died/got damaged.

 

[zenrunner92]

We have no idea, where and how you were connecting those fans.
Provide photos.
(upload to imgur.com and post link)

If there was a popping sound and burning smell, then probably something died/got damaged.

Antec NX410 case, has 3 fans which are daisy chained out of the box and sharing a single SATA power cable. I had stupidly disconnected them and plugged one of the cables into one of the mobo's fan headers.

The short happened when I tried to connect two unused 4 pin male connectors together, one for the 2 front fans and one for the 1 rear fan (which was the only fan working at the time) thinking this would allow the front fans to receive power and work too.

(It was like 2am and I probably should've gone to bed long before, lol.)

What I discovered the next day when I was less stupid, was that the rear fan cable that I had plugged into the mobo which was doing nothing anyway, was the one that needed to be reconnected to the front fans' cable.

Turns out the fans are designed NOT to connect to the mobo at all, other than one cable for the RGB lighting, since they are single-speed and always-on (neither of which was known to me nor stated anywhere in the product literature).

The two spare unused 4 pin connectors are likely there in case I wanted to add 2 additional case fans.

 

[Misgar]

I'd be more worried about the motherboard than the PSU. Most ATX PSUs have built in short-circuit protection on all the supply rails, which was probably triggered when you shorted out the supply. Mind you, on the 12V rail, the OCP won't kick in until tens of amps are flowing.

As a rough rule of thumb, if your PSU can supply all 750W @ 12V, that's 62.5A. Add another 10% to 20% for overload margin and OCP might not trip until the current reaches 69 to 75A. That's more than enough to cause magic smoke.

If the fault current flowed through the motherboard, it could easily have destroyed some components or melted some tracks. If the short circuit current only flowed through some wires, check for melted insulation on the fan cables or damage to the fans themselves. Replace anything that looks suspect.

Of course you might be very lucky, but be prepared for additional expense.

 

[zenrunner92]

I'd be more worried about the motherboard than the PSU. Most ATX PSUs have built in short-circuit protection on all the supply rails, which was probably triggered when you shorted out the supply. Mind you, on the 12V rail, the OCP won't kick in until tens of amps are flowing.

As a rough rule of thumb, if your PSU can supply all 750W @ 12V, that's 62.5A. Add another 10% to 20% for overload margin and OCP might not trip until the current reaches 69 to 75A. That's more than enough to cause magic smoke.

If the fault current flowed through the motherboard, it could easily have destroyed some components or melted some tracks. If the short circuit current only flowed through some wires, check for melted insulation on the fan cables or damage to the fans themselves. Replace anything that looks suspect.

Of course you might be very lucky, but be prepared for additional expense.

Huh, do you know how I can test if the motherboard is ok? Hoping any damage would be to nearby slots/sockets that I'll never use anyway, e.g. no plans to ever add a graphics card or additional SSDs or additional fans.

Come to think of it, the smell did seem to emanate more from the mobo than the PSU.

However, the system seems to be running fine, snappy and smooth and stable. HIW monitor shows temps remaining very low, mostly in the mid 20s to low 40s tops.