Horrendous Loud Gunfire Sounds, iMac Freezes

[Laisha]

Every now and then, for no reason we can discern, my husband's iMac makes a godawful and VERY loud sound like rapid gunfire, and at the same time, it freezes up completely. The only way to make it stop is to hold the on/off button down until it turns off.

Here is his computer's information:

OSX Yosemite
iMac (27-inch, Mid 2011)
Processor: 2.7 GHz Intel Core i5
Memory: 16 GB 1333 MHz DDR3
Graphics: AMD Radeon HD 6770M 512 MB


Any clues?

 

[Taz Mangus]

Every now and then, for no reason we can discern, my husband's iMac makes a godawful and VERY loud sound like rapid gunfire, and at the same time, it freezes up completely. The only way to make it stop is to hold the on/off button down until it turns off.

Here is his computer's information:

OSX Yosemite
iMac (27-inch, Mid 2011)
Processor: 2.7 GHz Intel Core i5
Memory: 16 GB 1333 MHz DDR3
Graphics: AMD Radeon HD 6770M 512 MB


Any clues?

Sounds like the hard drive might be failing. The drive head is banging which is probably what you are hearing.

 

[Ledgem]

It could be an issue with the hard drive, but it may also be something else. When the computer freezes, it tends to make a stuttering sound, particularly if audio was being played. Does it seem as if the sound is coming from the speakers, or from within the computer?

If it's from within the computer, it may very well be a hard drive issue. If it's from the speakers, then something is causing the computer to crash. It could still be the hard drive doing it, but it may also be something else, like corrupt RAM. Sounds aside, have you or your husband noticed any triggers for the crashing, or any pattern as to when it occurs?