White noise/Buzzing from internal speakers when audio output in use

Hello & thank you for taking the time to read over my post.

I recently fixed up a MBP A1297 (17” Unibody Mid-2010) that a friend spilt liquid on, changing out the top case as the keyboard backlighting & touchpad no longer functioned properly.

Everything went back together without issue & the 1TB SATA drive running a cloned version of High Sierra is seemingly working perfectly but I’m having a couple of issues that I’d like to get ironed out. After countless hours of research along with much trial & error, I’m no closer to figuring this out so I’m turning to the forums hoping an explanation of my specific issues will find it’s way to someone who knows what the beep! is going on & is willing to school me.

Issue 1:

I’m getting this annoying white noise/hard drive operation type sound intermittently. Intermittently with normal, no purposely triggered audio but it always happens when I start listening to something through the internal speakers (even if I put sound on mute. If something playing in the background, speakers are making that sound), usually lasting 30-45 seconds or so after audio is manually stopped.

YouTube Link for actual sound: https://youtu.be/h31hKBlR9qk

If I leave the sound (iTunes, YouTube, etc.) playing, the noise continues. I have not noticed the sound issue when using bluetooth or wired headphones nor does the sound come through internal speakers when utilizing headphones. Disconnect & the sound starts immediately through the internal speakers. There is also a very short occurrence of the sound with the start up/boot tone.

I have read SO many threads & watched so many videos on similar issues other users are experiencing but none that I’ve found thus far are the exact problem I’m having or that the proposed solution doesn’t solve my issue.

I have tried the NVRAM reset then starting it up in Safe Mode & audio output was disabled while in safe mode but I was able to get YouTube to play a video & there were no sounds coming from the internal speakers at all. Not sure if that’s telling me there is a software issue or just a result of limited functionality while in Safe Mode.

When listening to the audio through YouTube, please keep in mind that the fans are operating normally & running quietly. This “white noise” sound, sounds different in person. My phone makes it sound more like a loud fan which I can assure you, it is not.

Issue 2:

It’s not going into sleep mode when I close the lid.

Like the noise issue, I have put in more hours than I care to admit into finding a solution to this issue, trying everything I could find that did not require me to install third party software or delete files that may turn out to be integral to no avail. Everyone is a pro online so I proceed with caution when taking any advise provided on the web.

I’m hoping to have more luck here because I am burnt out on searching for the answer.

Please advise if any additional intel is needed to sort this out.

Any help is greatly appreciated, thank you!

Hello Dan,

I removed the bottom cover, running nice & quiet, pulled up a youtube video & as soon as it started, the sound started. While the sound was going strong, I listened on the uncovered underside directly below the left speaker & I could just barely hear the sound coming out of it. As soon as my head was back on the upper side of the case, sound was loud & clear. Insulating components.

As for TG Pro, I have not heard of it but I will check it out & see if I can get any change out of it.

For the second problem, I believe I understand what you’re telling me to do & that I’m executing the task properly but nothing is happening. I was perviously aware that Apple utilizes magnets to trigger sleep mode so I get the concept. The magnet on the screen is just where you said it would be but the magnet is not catching anything on the top side of the case where the screens magnet would make contact. As I typed that I remembered I took pictures of the underside of the upper case before I started work & there is no metal strip on that side. There is however, one on the front right side & another on the left side front of the touchpad. I am also getting magnetic hits on the areas of the screen that would line up with the metal strips previously mentioned. Am I correct in assuming that if the magnet has no metal strip to make contact with that it will not initiate the sleep mode action? If so, is the one that you mentioned critical or can one or both of the others git er done? Either way, lining up the paperclip & magnet didn’t do anything so may not be the main issue causing the failure.

I checked the IR cable & it looked to be completely seated & the retaining flap was engaged but I went ahead & popped it out & reinstalled with no luck. For the !&&* of it, I gently nudged it while the retaining flap was secured but the cable moved freely as if it wasn’t being compressed. I then closed the lid & put different types of pressure on it seeing if it would make the contact & put it to sleep but nothing I did phased it.

All considered, any new thoughts?

I put this in the comment section of your reply but I’m over double the character limit so posting an answer to my own question…….