So, as the title says, for no apparent reason, the speakers on my 2.5 week old 13" cMBP have started making a popping noise when I play videos, play any games that output sound, etc. It makes these popping noises for a few minutes (5-10 minutes) and then the sound completely cuts out and stops working, upon trying to put the volume up or down, it doesn't work. No sound comes out. If I restart the computer, the sound icon is "grayed out" and I can't change the volume by clicking the icon in the menubar. If I use the hardware keys, it shows the speaker symbol along with all the little bars as maximum, and under the bars indicating how high the volume is, there is a circle with a line through it, indicating that there is no sound output device. I checked the sound pane in System Preferences and it says "No devices detected". Also, the in the sound input tab, the built-in mic is detected, but doesn't respond to sound, so it doesn't work either, although it is detected... for now. I've checked to see if there is a red light in the headphone jack and there is none. I've even plugged headphones in and jiggled them around to see if that'll fix the issue. It hasn't. I've rebooted MANY times, reset the PRAM and SMC many times. I've googled around to see if I could fix the issue, and the most that I can do is just reset the SMC which seems to make the internal speakers begin to work once again, although only for a few minutes, and then they die out again and stop producing sound, repeating the whole process. I've deleted .plists that might be affecting the issue as suggested by some people that also had issues, etc., etc. NOTHING IS WORKING! I'm running Mountain Lion GM, and have been running it since it was released, so pretty much I've had ML running on my cMBP for the last 2 weeks and this issue just started happening tonight, so I know it's not caused by ML. If this issue persists, I'm just going to make an appointment at my local Apple Store for Wednesday (tomorrow) (since that's when ML will be released, because if I go in there today, I know they're going to make a fuss about it and say that I should wait for ML to be officially released, or to downgrade back to Lion). If you guys have an suggestions, I'm willing to try them, as I love my cMBP so far, but IMO it seems like this is a defect with my cMBP that can't be fixed other than by getting a replacement. Quick question: My brother broke my external HDD and it now is no longer identified by either my PC or my Mac, therefore I have no way to back up my data (in case I get a replacement cMBP and need to transfer my data). If I bring my cMBP to the Apple Store and they give me a replacement, can they transfer over my files for me to the new replacement cMBP? Thanks.