Chosen Solution
So this is whats been happening all of a sudden overnight… https://streamable.com/ya7ay When I plug in my headphones and open iTunes, the headphone jack doesn’t work (Tried 2 different headphones) I played around with the sound settings - muting sound, microphone etc to no avail. This “static sound” comes from both speakers and comes on when the Mac plays a sound file (notification) iTunes or a website that has media files on it. When the notification or song finished, the noise continues for another 20 seconds before it turns of. When I play songs or divert the sound to a bluetooth speaker it works perfectly. I have done a NVRAM reset but didn’t do the job. Update (03/18/2019) Morning guys, I sincerely appreciate your help! So I first did the SMC reset and during restart no static noise occurred when you hear the chimes when the Mac first starts up. I then installed VLC and played a random song and although the static sounds now sounds more faint it still remains there. I then opened iTunes, same static sound, same level of static noise on both speakers.. It also appears in internet browsing, when there is a commercial thats playing or a sound file. It starts as the same time the notification or commercial does, then turns off 20 sec after.…..am starting to think it is the power board and socket?…. I have nothing else attached to the 6 plug power board except a lamp. I should try relocating the Mac to another room and try a different power socket? Update (03/18/2019) I have put the iMac in the kitchen and plugged it in there, no static noise through the apple chime but as soon as I open iTunes, a website or a notification comes on so does the static noise, however it seems more faded. the intensity of the noise seems to vary. I believe it might be an issue on the logic board. I attempted to log out and log into a guest account to see if its a software issue however it does the same thing. frustrating! If I knew where on the logic board the problem is located I would take it apart and inspect it.
Is your alert or music able to play at all, or not without the static playing. If not I’m thinking the amp logic on the logic board needs repairs. Or, I’m thinking the headphone jack is damaged. Are you constantly plugging/unplugging headphones or external speakers into it? If you suspect thats the issue then you might be able to fix it by cleaning the switch elements within it
This is normal, but it should be quiet. The speakers are triggered by an application to turn on, so it makes quiet static. If this is loud, try resetting SMC or PRAM.
