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MacOS Site Admin

Joined: 19 Jan 2005 Posts: 304 Location: Berlin, Germany
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Posted: Sun Mar 25, 2007 10:00 pm Post subject: Macintosh Classic II squeaking problem |
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Hi there,
I have bought a nice Classic II, but after switching it on it starts
to squeak for a few seconds, the hard drive is running and the system is
booting. If the Classic II is running it squeaks in a sequence of c. all 60 seconds for about 5/8 seconds.
The Classic is in good condition, seems good handled over the years.
The shipping was ... ok - maybe the Mac had a hard tour.
I have opened the Classic II
to localize the source of the squeaking sound.
It is based at the analog (video) board left side of the Mac Classic II.
It seems not to come out of the speaker!
I disconnected the speaker and the squeaking remained.
Here is a video:
http://www.youtube.com/watch?v=c-Idzb5kL5E
As I shot the video I thought it came out of the speaker.
Does someone ever heard of that problem? _________________ MacOS aka Oliver

Last edited by MacOS on Sun Jun 17, 2007 12:16 am; edited 3 times in total |
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applefreak

Joined: 11 Oct 2006 Posts: 59 Location: belgium
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Bolle

Joined: 08 Jun 2007 Posts: 8 Location: Strausberg b. Berlin
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Posted: Sat Jun 09, 2007 2:04 pm Post subject: |
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sqeaking speakers are most times caused by bad capacitors. you should inspect your mobo for leaking caps and clean it if there are some. if the problem still exists after cleaning you should replace the old caps. |
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MacOS Site Admin

Joined: 19 Jan 2005 Posts: 304 Location: Berlin, Germany
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Posted: Mon Jun 11, 2007 10:08 pm Post subject: |
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Hi Bolle - thank you for the info.
It seems not to be caused by the speaker itself
if I disconnect the speaker cable the squeaking remains... _________________ MacOS aka Oliver

Last edited by MacOS on Sun Jun 17, 2007 12:18 am; edited 1 time in total |
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MacOS Site Admin

Joined: 19 Jan 2005 Posts: 304 Location: Berlin, Germany
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Posted: Sun Jun 17, 2007 12:11 am Post subject: |
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Some more details about my squeaking Mac Classic II:
The Motherboard squeaks! The capacitors look like they have lost some liquid that is now attached to the logic board.
I added the logic board to another Classic II an it starts to squeak emidiatly.
So it seems not to be the analog board - on both machines the display is sharp.
The squeaking is coming out of the analog board but it is based on a partial defected logic board.
I think I replace the capacitors and have a look if the squeaking remains.
Let you know. _________________ MacOS aka Oliver
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Bolle

Joined: 08 Jun 2007 Posts: 8 Location: Strausberg b. Berlin
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Posted: Wed Jul 04, 2007 7:48 pm Post subject: |
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dont forget to get the conductive goo that leaked from the caps off from the board. maybe you want to try to wash it before you replace the caps? use some isopropyl or wash it with water+soap - after that rinse with clear water to get ALL the soap off. let it dry for a day or two and should be OK again.
edit: really works: http://www.flickr.com/photos/21088395@N00/647796643/  |
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MacOS Site Admin

Joined: 19 Jan 2005 Posts: 304 Location: Berlin, Germany
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Posted: Wed Jul 04, 2007 10:22 pm Post subject: Thanks |
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Thank you for the details, I will use a Mac Classic II for a RetroChallenge Project - the Classic¥s Motherboard will be replaced (it produces a striped screen) with a Performa (68040).
So I have a good test board to learn some solder skills
Thanks for the photo - SE Geeks out there - have a look what Bolle did to repair his SE :
 _________________ MacOS aka Oliver
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