Apple's MacBook Pro users have been complaining about an unusual "popping" sound coming from their laptops. One of the users compared the sound to the "clicking" or "creaking" noise similar to slowly squeezing a plastic bottle. Apple has, reportedly, identified the cause of the issue which is a small dent on the bottom casing hitting the cooling fan. However, this is not covered under warranty.

Due to the issue, numerous annoyed customers took their complaints to the Apple's support discussion board as well as other forums to fix the disturbing noise, reports 9to5Mac. According to the complaints, the issue is experienced mostly in the latest 15-inch MacBook Pro model.

Before Apple identified the issue, the community had been totally unclear about the cause. However, one common thing the users shared was that the sound tended to occur during more intensive tasks like gaming, and image and video editing.

In one user's own words: "When I use the laptop in my lap and the fan comes on, I notice occasionally clicking occurring on the right side, near the top of the speaker grill. It almost sounds like what you would hear when metal expands/contracts when heated (like an oven). I can't reproduce it on demand, but  it will start doing it randomly."

Some MacBook Pro owners experiencing the issue, however, speculated that the noise might have been coming from the display hinges. Another user said that he was having this problem as well and it happened frequently while opening the laptop, and then later randomly. He thought that it might have been related to warming up from use.

Although Apple has identified the issue, the issue continues to persist because the dent is not covered under warranty. A MacBook Pro owner said that he took his laptop in to the genius bar for this popping noise where, after telling him the cause of the issue, they told him that he had to replace the entire bottom casing for $130 and that it was not covered under warranty because it was user inflicted damage or a wearable part.