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Squeaking Classic II

Squeaking Classic II Hardware 10 posts Nov 11, 2007 — Nov 13, 2007
That Classic II thinks its a kettle!

Thats been on youtube for a while.We had talk about that here:

http://68kmla.org/forums/viewtopic.php?t=2203

One of mine does that too.
Nah, mine doesn't squeal like that; it just crackles sometimes. That'd totally suck if it squealed like that though seeing as how much I use it!

Thats been on youtube for a while.We had talk about that here:

http://68kmla.org/forums/viewtopic.php?t=2203

One of mine does that too.
Nah, mine doesn't squeal like that; it just crackles sometimes. That'd totally suck if it squealed like that though seeing as how much I use it!
One of mine is WAAAYY worse than that. I just learn to ignore it.
If I had to hazard a guess, I'd say it was capacitor-related. Large filter capacitors in the power supply circuitry can often make a whistling noise when they start to go bad. I've had a few that have done it in peecees, though I never tried to actually replace capacitors; I just replace the PSU.

However, since we're talking antique Macs, I'd be more likely to give shooting and replacing them a go. It would be a bit of a craps shoot as to which ones were bad just on the whistling alone, unless there was obvious damage or leakage, or someone used an oscope on them. The only oscope I've got is a tube-based model from the 50s, and I don't think it works anymore, so I'd just replace 'em all, cuz I'm crazy like that.

Kettle? More like a pressure cooker...I've got one of those and it squeaks like there's no tomorrow...but it makes some mean green beans!

More likely it's a coupling capacitor, not a bypass capacitor, that's causing the squeal. There's a cap in series with the speaker (IIRC), and if that starts to fail in a certain way, it can produce belches, whistles, howls, crackles and other annoying sounds.

Nothing more than a worn capacitor in the sound circuitry as suggested previously. My Mac LC does it all the time, i've become used to it. Made it's choice of nickname easy anyway... "Squeaky". :p

mp.ls