Laptop AC DC converter putting out AC current

[vanuma]

I have had an Acer for about 5 years now. One day I got an AC shock from my laptop - when touching any metal parts like USB ports, Ethernet port etc. Turns out that the AC DC converter is putting out a AC voltage (used a simple tester to verify this).

So, went out and bought a new AC DC converter. Checked it out on another Acer laptop and it worked fine. Plugged it into this Acer, seemed to work fine, then in the middle of work, the laptop simply shut down. The little light on the converter was very low and blinking. Disconnected the laptop, the light came back to normal but continued blinking. Now the new converter is also putting out AC current.

I connected a different laptop's (also Acer) converter and that one's light started blinking too, but the laptop battery light did not come on. Did not want to lose another converter, so disconnected the whole thing.

Any ideas ? Help !

 

[sizzling]

Are you always using the same mains socket at the wall? I would be suspicious of your wall sockets earth being at fault? I doubt the converters are putting out AC as I suspect this would kill the power circuit in the laptop but you could have an earthing problem.

 

[jarotech]

Hi, do you have a hub or something else with a transformer connected to your laptop ?

 

[vanuma]

Are you always using the same mains socket at the wall? I would be suspicious of your wall sockets earth being at fault? I doubt the converters are putting out AC as I suspect this would kill the power circuit in the laptop but you could have an earthing problem.

I tried different sockets, and am pretty sure this is not a earthing problem, because the other Acer laptop I have works fine in the same sockets. Other appliances work fine at the sockets.

To test the converter, I plugged it into a wall socket (tried more than one), and left the DC output unplugged. Touched the metal part of the DC socket with a AC tester, and the tester lights up. The tester does not light up with the working converter. Of course, this is after the inadvertent finger test....

 

[vanuma]

Hi, do you have a hub or something else with a transformer connected to your laptop ?

Nope. Nothing, straight from the wall socket. It is 220V though, I live in India. The converter rating is correct, I checked. It is three pin as well.

 

[nukemaster]

If you have a non contact meter(the ones that light up without actually being connected to the 2 contacts on the notebook plug), it may just see power that is not actually on the connector.

I have seen those things show power on things that are disconnected even.

If you have a normal volt meter, You would check to ensure you are getting 220 volts at the plug(mains) AND the correct voltage at the laptop plug(0.25-0.5 volts over or under is not an issue).

I am wondering if you have another issue. Lets say the laptop has a problem that is causing it to pull too much power(partial short maybe), The power supply may fail or shut down(this would explain why 2 units have failed).

I can not be 100% sure, but I do not think a switching power supply can fail in a way that causes it to pump out AC.

 

[jarotech]

^+1. I was wondering also for this problem, if you are not connected with a voltmeter directly to the output of the adapter, you won't see the real voltage it will deliver if you have an AC voltage.
To the OP, how do you manage a short with just the output of the adapter ? You must have two contacts for you to have a real shock. You could have a static shock but not a real shock. If you do have a real shock, you have a real problem.

 

[Mathew_83]

I have had an Acer for about 5 years now. One day I got an AC shock from my laptop - when touching any metal parts like USB ports, Ethernet port etc. Turns out that the AC DC converter is putting out a AC voltage (used a simple tester to verify this).

So, went out and bought a new AC DC converter. Checked it out on another Acer laptop and it worked fine. Plugged it into this Acer, seemed to work fine, then in the middle of work, the laptop simply shut down. The little light on the converter was very low and blinking. Disconnected the laptop, the light came back to normal but continued blinking. Now the new converter is also putting out AC current.

I connected a different laptop's (also Acer) converter and that one's light started blinking too, but the laptop battery light did not come on. Did not want to lose another converter, so disconnected the whole thing.

Any ideas ? Help !

I don't think it's the problem of your power socket or the ac to dc converters. I believe there is some problem with your laptop motherboard or circuits. I had a similar problem but it was because of the earthing issue, but in your case, as you've tried with different socks, it doesn't seem like the same issue. Try a visit to laptop service center.

 

[nukemaster]

4 Month old thread