Loud buzzing noise coming from Mac Classic

[Kouzui]

Hey guys, I've been using the Classic I restored lately, and in the past week or so it's developed this issue where it starts emitting a really high pitched whine after being on for a few hours. I'll attach a video of the sound.

I don't really know why it's doing this, and I don't see any display shaking or any other issues, the AB side of the computer doesn't feel hot either.

Anyone have any clues?

View attachment IMG_4233.mov

 

[imactheknife]

I don’t hear anything..unless the noise is not a constant..

 

[joshc]

I can't really hear anything untoward either... It's not uncommon for various analog board components to have some whine.

 

[Kouzui]

Lol, maybe I just have really good ears - but I don't think so. If you crank the volume you can hear a kind of tinnitus sounding fluttery EEEEEEEE sound over the roar of the fans. It's also quite loud IRL, more noticeable than even my worst CRT's whine.

 

[68kPlus]

I hear it! Then again I'm younger than most on here. I think that's just the CRT/flyback transformer whine.
Nothing to worry about. Does your CRT have a lot of hours?

 

[Kouzui]

Does your CRT have a lot of hours?

Frankly, I have no clue. It has very little burn-in, but there is some. I just find it odd that the sound only starts after it's been on for a few hours, as well as it being loud as hell. It's completely silent other than the fan normally.

 

[68kPlus]

Frankly, I have no clue. It has very little burn-in, but there is some. I just find it odd that the sound only starts after it's been on for a few hours, as well as it being loud as hell. It's completely silent other than the fan normally.

Interesting. Maybe a heat related thing that creates a gap in the flyback?

 

[Kouzui]

Maybe a heat related thing that creates a gap in the flyback?

Maybe. And if that's the case, I'm probably just gonna have to live with it. Unless someone is selling low-hour flybacks at less the price of a whole computer, I don't see it getting replaced.

 

[RubyRoo]

Maybe. And if that's the case, I'm probably just gonna have to live with it. Unless someone is selling low-hour flybacks at less the price of a whole computer, I don't see it getting replaced.

Perhaps my track-record with macintosh currently doesn't validate me to offer some assurance but as someone who works on CRT's in arcade monitors. That just sounds like regular monitor noise/flyback. If you were to adjust the voltage (i'm assuming the classic has one like the plus) or the monitor picture You may notice that the noise becomes higher or lower in pitch depending on the value of it but it's pointless to do so in my opinion unless your macintosh isn't getting the voltage it needs.. In pretty well every CRT monitor or television i've ever worked on or used i've heard a high pitch whine like that sometime or another.

 

[Kouzui]

In pretty well every CRT monitor or television i've ever worked on or used i've heard a high pitch whine like that sometime or another.

Same... with the exception of compact Macs. All of the ones I own are silent. I don't know if it's because it's black and white or something, but they don't have the same buzz that all of my other CRTs have.

 

[joshc]

Bear in mind the Classic was built with cheap components; it was a cost cutting exercise from top to bottom.

 

[LaPorta]

I can hear what you are talking about, and if it is louder in real life, it is louder than anything I normally hear from a compact. At the same time, I don't think there will be any sort of easy "fix" for you. Might just be components unique to this machine, as others said.