On Monday, Oct 14, 2002, at 18:28 Europe/London, Spiritus ex Machina 
wrote:

> Folks,
>
> I'm doing some volunteer work at my son's school, trying to keep some
> venerable hardware in use.

Good man - this week's notional Mars bar to you - and it's only Monday! 
:).

> I've got an LC that I'm trying to set up
> for the kindergarden class to use for practicing keyboarding and
> mouse manipulation.

Awwwww. That's too cute - it makes me fell all fuzzy inside. My niece 
is at 'playschool' which is essentially the same thing as KG. We have 
made a point of getting stuff for her to play with on my dad's machine. 
It's good practice in a modern world where everyone is expected to be 
able to use a computer.

> It starts up with a satisfactory 'Bong!' and seems to be running
> System 7.5.5 with no problem.

Ee gods. Put 7.1 on it. I know they aren't likely to know the 
difference but  the mouse might actually keep up with the hand 
movements if you do ;)

> However, it starts screaming and
> squealing like an AM radio in a really bad reception area. The
> problem is definitely in the sound generation, not the hard drive
> bearings. (I swapped hard drives to no effect; removed sound/fan
> module and problem went away).
> Can anyone suggest a way to fix this? Certainly I can clip the
> speaker leads, but then the soothing 'Bong!' goes away. :-(

Try this for size. the wires are in pairs coming off the logic board. 
Try sticking a folded bit of paper under one pair (one pair is blue+red 
the other is black+red) and seeing which pair makes the noise go away. 
If it's the black+red pari it's the sound system/speaker, if it's the 
blue+red pair it's the fan.

If it's the fan rob another module and try it. The fan can be swapped 
by removing the fan itself from the frame and then getting a small 
screwdriver and pushing in on the two clips at the inside of the 
contact housing on the two metal tabs that correspond to the fan wires. 
The wires just unclip from there and the fan is free. Do the same with 
a good fan and replace it. It's a lot of fiddle so it's probably just 
best to designate another machine for spares and swap em out.

If it's the speaker then you can again swap the whole module or the 
speaker comes out in a similar way (you have to unclip the fan to get 
to the metal tabs). Also if the sound IS on the fritz then it might be 
an idea to clean the contacts on the board and the module with an 
electrical cleaner. DON'T use abrasive on the pads on the logic bard as 
you will bring it off, it's only solder IIRC.

If all that fails check the logic board for dry joints.

> Is this
> an indication that bit-rot is setting in and that I should just part
> out the box to salvage other boxes? I have absolutely no money for
> 'upgrades'. Repairs will have to be made out of salvage or my own
> resources.

Nahh. Just needs a little TLC and transplant work.

-- 
Mark Benson

AIM - SilValleyPirate

Visit FlatPackMacs online:
<http://fpm.gotdns.com>
Mac LC Central
My homepage:
<http://homepage.mac.com/markbenson/>


-- 
Vintage Macs is sponsored by <http://lowendmac.com/> and...

 Small Dog Electronics    http://www.smalldog.com   | Enter To Win A |
 -- Canon PowerShot Digital Cameras start at $299   |  Free iBook!   |

      Support Low End Mac <http://lowendmac.com/lists/support.html>

Vintage Macs list info: <http://lowendmac.com/lists/vintagemacs.shtml>
The FAQ:                <http://macfaq.org/>
Send list messages to:  <mailto:[EMAIL PROTECTED]>
To unsubscribe, email:  <mailto:[EMAIL PROTECTED]>
For digest mode, email: <mailto:[EMAIL PROTECTED]>
Subscription questions: <mailto:[EMAIL PROTECTED]>
Archive: <http://www.mail-archive.com/vintage.macs%40mail.maclaunch.com/>

Using a Mac? Free email & more at Applelinks! http://www.applelinks.com

Reply via email to