Laptop charger makes unusual noise

[SabrinaF]

My laptop (Asus) charger makes an unusual noise like electrical short inside it. This is my second charger and my original charger was damaged sometimes ago. I purchased this from a second-hand item selling shop. So, I don't know further details about the charger. It worked fine for several months and now, I have this problem

[Jeff]

Does not sound good, chargers should not be making any noises.
I would recommend buying a brand new charger. You would get at least a 1 year warranty. When buying a charger make sure it outputs the right voltage and amps, if not right you could end up with more problems. You should be able to get these off the old charger. Don't let price dictate what you get, cheap products are cheap for a reason, usually because they have the bare minimum of components to do the job. PB Tech have ASUS chargers, so that is one place to try for a replacement.

[SabrinaF]

Thank you very much for your response. I have already used this for 2-3 months along with the noise without taking it into account. Because there wasn't any charging issue. Anyway, it seems that I shouldn't move further like this.

[Kame]

You say it worked fine for months, so this noise has only just started?

I wish I knew what you are hearing but since electrical deaths/fires are no fun and I can't recommend poking around inside the laptop, the charger or with your mains power. All are possible culprits.

[Agent_24]

The charger is probably on the way out, especially if it did not do that before.

That said, while power supplies should not typically make noise, sometimes they will make hiss, buzz, or humming noises during normal operation, depending on the design. But that would be the case from day one.

It's hard to say from your description. What does "a short" sound like to you? To me, a short sounds either like the silence of a blown fuse, or a loud bang as a power transistor explodes.

I can only guess you mean electrical arcing or such, with a snap, crackle or fizz noise?

Since the charger still charges, my guess would be on a bad solder connection at the AC socket. On a lot of chargers, this socket is only soldered to the PCB and has little mechanical support. Over time and with many plugging in/unplugging cycles or rough use, these connections can crack. Then you get arcing in the damaged connection. Eventually, the connection will burn away completely and the charger won't work at all.

[Kame]

I think you mean DC socket, the port the charger plugs into on the laptop. That was my initial guess because it'd be such a shame to buy another charger as suggested.

In some cases, the charging board can just be replaced. If not, then you have to solder the port back on. Given that is the actual problem.

So it may involve poking around inside the laptop, the charger or your mains power. Even though, it is easier to test in reverse order but again, electrical deaths are not fun.

[zqwerty]

No, he did mean AC socket on the charger, in my experience hissing and fizzing noises are often caused by a bad solder joint on one or both of the AC input terminals that have been roughly handled because of many plugging ins and unpluggins over the years of use.

This often happened with PlayStation 1's years ago.

[Agent_24]

I did mean AC socket. I've opened/repaired many chargers and it's a common problem.

It's one of the few faults where a charger could make obvious noises but still work (for a while). Most audible problems in switching power supplies are marked with a bang, followed by nothing working at all.

Yes, you could get the same bad connection/arcing at the DC side too but it's less common and likely won't generate as much noise due to the lower voltage.
Easy to tell which one though, just extend the charger cord all the way and listen to both the charger and the laptop. Should be obvious which end the noise is coming from.

Some better designs connect the AC socket with flying leads so mechanical strain is all but eliminated.

But when the socket is directly PCB mounted, it must have decent mechanical support, screws, clips into the case etc, otherwise solder cracks happen eventually. Solder is NOT welding, it provides a good electrical connection but a poor mechanical one.