What happens when 12V and GND are both connected to the GND pin?

[grasscut]

I would like to know what will happen when i accidentally connected a 12v and GND to a 4 pin molex, in its GND pin. The picture is the example of the 12v 4 pins connector. I accidentally plug my 12v and gnd wire to the respective pin 1 and 2 of the ATX connector. Will it cause my circuit board to burn? does this makes an short circuit? hope someone can example to me. thanks!

 

[cnh1995]

If pins 1 and 2 are internally connected, then yes it will create a short circuit and it might burn the power source cables and damage the power source (or trip its fuse).
Do you have a digital multimeter? You can check the 'continuity' between pins 1 and 2 using the multimeter.

 

[grasscut]

If pins 1 and 2 are internally connected, then yes it will create a short circuit and it might burn the power source cables and damage the power source (or trip its fuse).
Do you have a digital multimeter? You can check the 'continuity' between pins 1 and 2 using the multimeter.

So do you mean that only the power, in which i used a DC adapater, will be damage only? the circuit board should be fine?
I did use a multimeter to measure the continuity of pin 1 and 2. pin 1 is connected to chassis and pin 2 is connected to a dc plug. it doesn't seems like both ground are connect. not sure if is internally connected though

 

[cnh1995]

So do you mean that only the power, in which i used a DC adapater, will be damage only? the circuit board should be fine?

Well, the portion of the circuit board carrying the short-circuit current may get damaged. But if you are inserting power source cables directly into pins 1 and 2, the circuit board should not get damaged.

I did use a multimeter to measure the continuity of pin 1 and 2. pin 1 is connected to chassis and pin 2 is connected to a dc plug.

Did the buzzer sound when you put the multimeter probes on pins 1 and 2?

 

[grasscut]

Well, the portion of the circuit board carrying the short-circuit current may get damaged. But if you are inserting power source cables directly into pins 1 and 2, the circuit board should not get damaged.

yes, i did insert 12v cable into pin 1 and the negative gnd to pin 2. hopefully it doesn't damage the board like you said.

Did the buzzer sound when you put the multimeter probes on pins 1 and 2?

Unfortunately, that i didnt measure.. if they are connected then likely it will damage the component? Its quite likely that a common ground is used yeah?

 

[cnh1995]

Its quite likely that a common ground is used yeah?

Yes, it is very common to connect all the grounds on a board together.

Unfortunately, that i didnt measure.. if they are connected then likely it will damage the component?

if they are connected then likely it will damage the component?

It will damage the supply or trip its fuse.

 

[grasscut]

Yes, it is very common to connect all the grounds on a board together.It will damage the supply or trip its fuse.

its okay to damage the power supply. as long as the board will be fine. my concern is more on the board itself. fortunately, i didnt see any sparks or burn smell.

 

[anorlunda]

its okay to damage the power supply. as long as the board will be fine. my concern is more on the board itself. fortunately, i didnt see any sparks or burn smell.

We can't give you a definite answer because we don't know how much short circuit current the supply provided, nor how long in time, nor how much current it takes to damage the board.

 

[rbelli1]

Unfortunately, that i didnt measure..

Measure the resistance from pin one to pin two with nothing else connected. If the resistance there is about the same as the resistance with just the meter leads shorted then you should be fine. This resistance should read much less than one ohm.

Even if you burnt a ground pin you may still be fine. The one pin may be enough to run the equipment. It is advisable to repair any burnt connection to the connector.

BoB

 

[grasscut]

We can't give you a definite answer because we don't know how much short circuit current the supply provided, nor how long in time, nor how much current it takes to damage the board.

I used a power supply with 12V and 2A. but yea. i don't know whether the internal connection is damaged or not

Measure the resistance from pin one to pin two with nothing else connected. If the resistance there is about the same as the resistance with just the meter leads shorted then you should be fine. This resistance should read much less than one ohm.

Even if you burnt a ground pin you may still be fine. The one pin may be enough to run the equipment. It is advisable to repair any burnt connection to the connector.

BoB

I tried to do a continuity test between pin1 and pin2, they are both common ground. hope the board is still in working condition.
I know if i mixed up my connection with the position and negative, it will definitely burn, but I am not sure what will happen since i put it into both pin which is ground.

 

[anorlunda]

With only 2 amps, you're probably OK.

Edit: but 2A is the current that the supply can deliver safely, without damaging itself. How much can it supply as it is burning out? Still, my guess is that you're OK but no guarantees.

 

[grasscut]

With only 2 amps, you're probably OK.

Edit: but 2A is the current that the supply can deliver safely, without damaging itself. How much can it supply as it is burning out? Still, my guess is that you're OK but no guarantees.

im not sure about how much it can supply as it burn out. i just saw the information on the dc adapter.
thank you all so much for the replies!

 

[CWatters]

What sort of power supply did you use? Some power supplies have short circuit protection so it might just shut down.