What happens if you short the 5v and GND on a molex while running?

[Coup27]

I have just finished building a PC for a friends 14 year old son using a case with lots of lights and trinkets. One of the LED strips stopped working after 2 hours. I discovered that the molex connector for the LED strip was crimped very badly (as usual) and the cables fell out with a minor pull. I tested with my multi meter that I had 5VDC across red and black so I knew the PSU was not the culprit.

I stripped new ends cable ends on the offending LED strip and tried to carefully dab them on the red and black to see if the strip would come on. My dog then decided that was the perfect moment to come and say hello and bumped into me and I shorted the red and black together.

The PC immediately rebooted. I've been using it since then and everything appears to be working fine. I've used a Haswell CPU, Asus 8 series motherboard and an old Antec Earthwatts 500W PSU (EA-500) I had in stock but no home for it.

Can somebody please advise on whether this would cause any damage to the system or whether the PSU has a built in protective system to prevent damage?

Many thanks.

 

[ericloewe]

The Earthwatts have a decent reputation, from what I remember... Any decent PSU has short-circuit protection, so no more damage than the typical sudden power failure. If everything's working fine, everything's most likely fine.

 

[SecurityTheatre]

I have just finished building a PC for a friends 14 year old son using a case with lots of lights and trinkets. One of the LED strips stopped working after 2 hours. I discovered that the molex connector for the LED strip was crimped very badly (as usual) and the cables fell out with a minor pull. I tested with my multi meter that I had 5VDC across red and black so I knew the PSU was not the culprit.

I stripped new ends cable ends on the offending LED strip and tried to carefully dab them on the red and black to see if the strip would come on. My dog then decided that was the perfect moment to come and say hello and bumped into me and I shorted the red and black together.

The PC immediately rebooted. I've been using it since then and everything appears to be working fine. I've used a Haswell CPU, Asus 8 series motherboard and an old Antec Earthwatts 500W PSU (EA-500) I had in stock but no home for it.

Can somebody please advise on whether this would cause any damage to the system or whether the PSU has a built in protective system to prevent damage?

Many thanks.

It's pretty unlikely this will cause damage. the worst case is probably just a voltage drop hit the motherboard which caused it to reboot. No serious damage, unless you were writing data to the drive at the time, as with any other reboot, it could be lost.

 

[Mushkins]

One more vote for it should be fine. The tiny short you caused shouldn't have done any permanent damage to quality hardware, and if it's working fine after the fact you should be ok.

 

[Smoblikat]

I would imagine it tripped the various protections in place and was cancelled before it caused any damage.

 

[VirtualLarry]

I would imagine it tripped the various protections in place and was cancelled before it caused any damage.

Should have used a whole-house earthing protector, then it might not have rebooted... oh, wait...

 

[Torn Mind]

Thankfully for you, someone did review and test the old EA-500 and found that its short circuit protection circuit did work on the 5v and 12v rail. Hence, I think it is safe to assure you that the PSU is fine.

http://www.hardwaresecrets.com/printpage/Antec-EarthWatts-500-W-Power-Supply-Review/526

Use CTRL+F and use the term SCP.
You will find:

Short circuit protection (SCP) worked fine for both +5 V and +12 V lines.

Accidents like these is why opening up the insides and testing PSUs is so valuable. The information can be used to evaluate and diagnose issues. And it is an example that a PSU is more than just about it "turning it on". Indeed, implementing ways to shut the PSU off when a abnormal state of the circuit occurs can be invaluable in saving the PSU, other components, and/or someone nearby.

 

[Torn Mind]

Should have used a whole-house earthing protector, then it might not have rebooted... oh, wait...

He(westom) would not have posted that because that is in regards to redirecting a huge amount of current before it gets to the components downstream from it.

Some of the assertions he makes are closer to the truth rather than falsehood. Indeed, it is always a defect that causes of those odd or premature failures of a PSU, mobo, etc.

 

[Coup27]

Thanks guys for the replies, especially Torn Mind.

 

[aigomorla]

ive done that..

the psu just cuts power and looks like it died.

then you need to unplug it.. and then replug it to get it started again.

Well i guess its mostly on the PSU you have.... but im fairly sure 90% of all the PSU's made for PC's do this.