macintosh analogue board reconditioning

From: r. 'bear' stricklin <red_at_bears.org>
Date: Wed Oct 24 21:15:58 2001

Howdy to the list (and especially to Tony)...

I have a Macintosh 512K I would like to use to demonstrate certain UI
principles (okay, and also to play Dark Castle). The display hasn't worked
properly since I got it though.

In an attempt to stabilize the image, I pulled off the insulating
fibreboard covering the sweep board, and looked for bad solder joints to
fix. The problem is I don't know what a bad solder joint looks like aside
from 'dull', and none of the joints look particularly 'dull' to me.

I reflowed a few joints randomly, with no clear sense of what I was doing
or where particularly to focus my attentions. Predictably it did not
change the behaviour of the image on the display noticeably.

I just in the last few minutes switched the machine on to photograph the
display for your expert appraisals, and found that its behaviour has
changed since it has sat. Now when I switch it on the internal speaker
makes a repeated popping. I'm guessing the power supply is resetting
itself continuously for whatever unknown reason.

I could use some guidance repairing this fault. What's my first step?
Tony, I'm a module swapper because that's what I know, and usually the
problems I have are in software anyway. I'm handy with a soldering iron,
though, and I'm showing a willingness to learn something new. Help!

ok
r.
Received on Wed Oct 24 2001 - 21:15:58 BST