[comp.sys.mac] Problem with speaker after memory upgrade

ichiro@codon4.berkeley.edu (07/06/89)

Today I upgraded an SE to 2.5 megabytes using SIMMS from Technology
Works. Everything went fine considering that this was the first time
I'd opened up a Mac, but after booting the machine I noticed that the
speaker was behaving erratically. Sounds would begin but would then be
cut short or degenerate into static. Sometimes I couldn't get any sound
at all. I opened the case again and checked the speaker cable
connection, but everything appeared to be in order. The problem was
still there when I started it up again.

Setup:  2.5 megabyte SE running System 6.02 (problem occurs under both
Multifinder and Unifinder)

A coworker suggested that there might be some oxidation particles on
the contacts. From experience with stereo hookups this makes sense, but
I wonder if anyone out there might have had a similar experience.  If
anyone does have any experiences or suggestions, then please e-mail
them to this account and I'll post a summary to the net.

Thanks in advance,

Elliot Wilen
ichiro@enzyme.berkeley.edu
...ucbvax!enzyme!ichiro

ichiro@codon3.berkeley.edu (Elliot Wilen) (07/15/89)

In article <26039@agate.BERKELEY.EDU> I wrote:
>Today I upgraded an SE to 2.5 megabytes using SIMMS from Technology
>Works. Everything went fine considering that this was the first time
>I'd opened up a Mac, but after booting the machine I noticed that the
>speaker was behaving erratically. Sounds would begin but would then be
>cut short or degenerate into static. Sometimes I couldn't get any sound
>at all. I opened the case again and checked the speaker cable
>connection, but everything appeared to be in order. The problem was
>still there when I started it up again.
>
>Setup:  2.5 megabyte SE running System 6.02 (problem occurs under both
>Multifinder and Unifinder)
>
>A coworker suggested that there might be some oxidation particles on
>the contacts...

First off, I should explain that the problem went away after a day or
so of use, which makes me think that it was indeed just a matter of
oxidation particles. But I did get several responses which might alert
people to some of the hazards to avoid when working inside the Mac.

Mark H. Anbinder (mha@tcgould.TN.CORNELL.EDU) suggested that I could
have punctured the the paper speaker cone with the pin on one of my
SIMMs. This definitely is something to watch out for, since the SIMMs
on an SE are mounted right next to the speaker, and the 1 Meg SIMMs I
got are also a little bit wider than the 256k ones which came with the
machine.

Stephen Sakamoto (steph@cs.ucla.edu) mentioned that there might be
oxidation particles in the external audio connector, instead of the
internal cable connection. Since the contacts in the jack act as a
switch to disconect the internal speaker, oxidation there could cause
the internal sound to go out. He suggested that I plug an external
speaker into the jack to see if the Mac was okay, then (if that worked)
try inserting and removing the plug a few times to clear any
oxidation.

Clark Anderson (anderson@apple.com) wrote that I might have blown the
sound chip with static while doing the upgrade. Thankfully this does
not appear to have happened, but the possibility is certainly something
to watch out for.

Thanks to Mark, Stephen and Clark for replying to my request for help!

--Elliot Wilen