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- Newsgroups: comp.sys.mac.system
- Path: sparky!uunet!gumby!wupost!udel!gvls1!dave
- From: dave@prc.unisys.com (David Lee Matuszek)
- Subject: Re: IIsi sound problem
- Message-ID: <1992Aug17.191610.1378@gvl.unisys.com>
- Sender: news@gvl.unisys.com (IEE news user)
- Nntp-Posting-Host: yggdrasil.prc.unisys.com
- Organization: Paoli Research Center - Paoli, PA
- References: <92224.205851BGD1@psuvm.psu.edu>
- Date: Mon, 17 Aug 1992 19:16:10 GMT
- Lines: 102
-
- In article <92224.205851BGD1@psuvm.psu.edu> BGD1@psuvm.psu.edu writes:
- >Sometimes my Mac IIsi becomes silent, regardless of the program that's
- >running--it happens even if the finder is the only "appl." running. Less
- >frequently, my Mac acts as if the sound control panel were set on 0 (i.e.,
- >the menu bar flashes). Resetting the volume to LOUD (6-7) and then back
- >down to 2 were I keep it solves the problem for a while. I've checked for
- >viruses. It's running system 7.0 plus TuneUp. Any ideas? thanks.
-
- ------------------------------------------------------------------------
-
- Time to post this again. [I revised it slightly to incorporate
- suggestions from other net folk. Thanks, everybody.] This needs to
- go in a FAQ list somewhere.
-
- It is a well-known phenomenon that the sound vanishes from time to
- time on the Mac IIsi. This happens under both System 6.07, System
- 7.0, and System 7.01. It occurs with or without System 7 Tune Up
- 1.1.1, and presumably with earlier versions of Tune Up as well. It has
- also been known to happen on the LC, but seems to be less common
- there.
-
- My experience is that the problem only occurs at lower sound levels (4
- and under). At levels 6 and 7, the problem never occurs. Also, as
- far as I know, the problem never occurs with external speakers. I'd
- be glad to hear from anyone whose experience is not consistent with
- this.
-
- The three main theories are:
-
- (1) Corrosion build-up on the speaker contacts.
-
- Those who maintain this suggest snapping out the hard drive above the
- speaker and carefully cleaning the contacts with a pencil eraser.
- This is really simple to do (I take no responsibility, of course), and
- you can clean the contacts for the disk light at the same time. (I
- also pushed my disk light into place so that it was more visible from
- outside; it hadn't been put in well.) My experience was that (1) the
- contacts looked perfectly shiny and clean, and (2) the problem did
- seem to diminish for a while. I think.
-
- The major problem with this theory is that the sound can be restored
- by software. Just open the control panel, turn the sound up loud, and
- turn it back again. I've heard it suggested that the higher volume
- "burns through" the corrosion, but (1) in my experience corrosion
- doesn't work that way, and (2) if it were corrosion I would expect a
- lot more randomness and in the effectiveness of this process; but it
- seems to be completely reliable.
-
- (2) Erroneous use of the sound manager by applications.
-
- IMHO, I think this theory is wrong. It is true that Apple has made
- incompatible changes to the sound manager, and many programs have
- broken on this. However, there is no discernable pattern to the sound
- drop-outs; it seems to happen (or not happen) to any program. The
- thing that most convinces me this theory is wrong, though, is that I
- entered the code for playing sounds straight from Mark & Reed's
- Macintosh programming primer (Pascal version), and I had the sound
- drop out when using that program. The source code is right there in
- black and white, and if anyone sees what's wrong with it, I'd sure
- like to know.
-
- Another problem with this theory is that it is hard to see why erroneous
- use of the sound manager would cause the sound to cut out on the internal
- speaker, but not on external speakers.
-
- (3) A persistent bug in the operating system.
-
- The main thing this theory has going for it is that the other theories
- don't seem to fit the facts terribly well. If this is the correct
- explanation, the only course is to wait for Apple to figure it out and
- fix it. I spoke once (via e-mail) to someone at Apple who said he was
- working on the problem; I sent him what I knew, but never heard from
- him again.
-
- The main problem with this theory is that there have been reports that
- banging the front of the computer sometimes restores the sound. I
- haven't tried this myself; I have too much respect for my internal
- hard drive.
-
- ADVICE:
-
- 1. Keep the sound level loud; this keeps the problem from occurring.
-
- 2. When the problem occurs, reset the volume to loud, then back to
- where you want it. Alternatively, download an FKEY from sumex
- that does this for you: it's at info-mac/fkey/reset-sound.hqx .
- DON'T bang the computer (there's a hard drive in there!).
-
- 3. Carefully clean the speakers contacts with a pencil eraser.
-
- 4. Use external speakers. Failing that, poke a jack of the proper kind
- into and out of the external speaker port a couple of times; some
- people report that this (temporarily) fixes the problem.
-
- 5. Hassle Apple to come up with a permanent fix.
-
-
- --
- And the President put his hand on my shoulder and said: "Dan,
- I _knew_ Spiro Agnew. He was a friend of mine. And Dan...
- You're no Spiro Agnew!"
- -- Vice President Dan Quayle
-