loud electronics pops

[GrayHare]

Before I start opening or replacing equipment I figured I'd ask the tech experts here for advice. Twice during the past week in my computer area I've heard a loud pop, about half as loud as a firecracker. The sound does not obviously emanate from one component otherwise I'd be closely checking that component. I can find nothing wrong. Everything works as before. There has been no burning or ozone smell before or after the pop. There seemed to be no electrical interruption during the pop, that is, nothing flickered. No electronic components, such as UPS, router, etc. are running hot. Everything seems normal except for the startling pop noise. Ideas?

 

[Lewis Clark]

Is it perhaps coming from the computer speaker? Speaker static can cause that type of sound.

 

[GrayHare]

I'd not considered speakers. Don't think so because the pop has a broad frequency range, larger than the speakers could produce. The general pop area has a UPS, router and multi-outlet surge protector. I have now disconnected the last of those.

 

[easysurfer]

My first thought was perhaps capacitors popping. But I'd think would have had a burnt electronics smell.

 

[GrayHare]

Agree re capacitor smell. I've fussed with electronics for decades and until now loud pops have always been accompanied by an odor. Not these pops, however. The first one happened while my UPS was reporting a slight overvoltage (124 volts), which made me suspicious. The most recent one happened during 121 volts. The UPS is 10 years old, maybe it's time for a new one?

 

[Texas Proud]

Can you check you wiring at the plug? IOW, take the plate off and even pull the plug out..

I had a short in a plug at my old house... I was lucky it did not burn the place down... eventually it produced a burning smell so I went to look... the thing was melting and was bad... there was nothing else near that plug so it was easy to find the problem...

 

[Al18]

I would immediately unplug the computer, open the case and look for burned components. The computer may still be operating, but it may only be short term. Don’t forget to check the power supply. If the computer is ok, I would check around the room with a thermal imaging camera, which can detect hot spots on devices, outlets, etc. Amazon has many models for $200-$300.

 

[GrayHare]

Good ideas, thanks, I have a thermal imager and will put it to use. The noise is more sharp bang than muffled pop, which makes me think spark, except this is way louder than all the 120 volt sparks I've ever heard. I'm also puzzled that there is no smoke or other odor.

 

[GrayHare]

Thermal results are normal. Warmest objects are the UPS and router, both 5 to 20 F degrees above ambient. I realized there is another device within in the general bang source area, a small space heater. That's a device that can draw a lot of current, but it is switched off and was used just once this month. I have now unplugged it.

 

[Sunset]

I also think it is the speakers, perhaps an external spark caused them to pick EM waves/pulse up via the speaker wires and translate that to sound.

 

[ERD50]

Any update?

 

[imjustawarrior]

Could it be a mechanical stress pop due to thermal expansion/contraction?

My TV does this about an hour after it is off just as I'm about to fall asleep at night.

 

[GrayHare]

It's significantly louder than thermal expansion pops. Have not heard it since unplugging the space heater, but since the pops I did hear happened days apart, insufficient time has elapsed to know if the heater was the source. I could disassmble the heater, but the lack of odor produced by the pops suggests nothing got burned, and thus I won't find any burn marks.

 

[GrayHare]

An update. No loud pops for over a week. The changes I made were unplugging a space heater and a power strip, plus swapping out an old UPS for a new one. Highest on my suspect list is the space heater because my one use of it this season came a few days before the first pop noise. FWIW the heater had not been plugged into the power strip.