Logitech Speakers the Culprit of My Short / Breaker Flip?

I want to start by saying I'm not a household wiring expert by any means. I understand DC but am not very good with AC. So, I may use incorrect terms - please be patient with my household wiring n00bness

Yesterday I heard 2 dull noises (sounded like 2 things fell on the ground) and then a circuit in my house turned off. After that, a brief electrical burning smell was there but it quickly went away. I wasn't sure what happened, so I unplugged everything, got rid of anything that I didn't absolutely need to be plugged into that circuit, then turned the breaker back on.

Everything went fine until about 24 hours later when the breaker tripped again. I then got out my multimeter and set it for continuity, then put the prongs in each of the affected outlets on that circuit. I got a buzzer, when putting it into each of the holes in the outlet, indicating to me (hopefully correctly) that there was a short.

I unplugged all devices one by one until the short went away. It was a part of Logitech 2.1 R-20 speakers with a small built-in power supply. No other device or cord hooked up to that circuit hat a short, but this device buzzed the continuity tester when i applied the test leads to either side of the prongs of the plug, leading me to think the device itself had a short. I took the speakers apart but didn't notice anything particularly odd.

Wanting to err on the side of caution I threw the speakers away and then re-checked (just to be extra sure) each device and no continuity buzzed on any of the plugs. I plugged everything back in, rechecked the outlets and again no continuity. I flipped the breaker back on and things seem to be OK. It's been about 12 hours.

My question is this - does it sound reasonable that the culprit of my electrical short / breaker flip was the speakers? I googled around a bit and noticed that there was a recall for that model in Australia only (I'm not sure why just there). They were old but otherwise seemed to work OK.

The reason I ask is that I want to be relatively sure that I've addressed the problem and minimize the risk of further issues / fire.

 

Sounds like a bad power supply not the speakers. Using a buzzer instead of checking ohms was not accurate enough to give useful information.

 

The power supply was in the speaker, so it wasn't a separate box.

 

The buzz might have been telling you you should not be checking continuity with the power on. Continuity is checked with the power off.

 

Is it an AFCI breaker ?

 

You also have to understand that one of the things in that speaker P/S is a transformer most likely. Trying to check one with just a continuity tester or a cheap multimeter set to the diode or "beep" function will almost always beep or buzz. Esp with a cheap tester. I just checked a couple of "wall warts" with my good Fluke meter and got an initial beep on 2 out of three til the meter settled down and gave a very low ohms reading.

Old power supplies could have a failed component. One test would have been to plug it in to a different circuit. Not going to burn the place down if it failed, esp if you are right there checking.