3 Jan
2008
3 Jan
'08
1:14 p.m.
Like what sort
of stuff? The most I ever saw those
fail was one company that
had a wire running from one building to another and
that used to pick up a
lot of transients from lightning. They'd bring
those terminals in fairly
regularly.
Mostly plugging/unplugging things with the power on,
and once a cable that got cut through by accident.
Static electricity zaps too, especially in poorly
grounded situations. I fell prey to this once myself. I had my Apple IIe connected to my PC through the
serial port. The Apple was running Kermit and acting
as a terminal to the PC. I have my chair on one of
those plastic mats on the carpet. I got up to go get
another cup of coffee, came back, sat down, and
wheeled over to the Apple II. I put my hand on the
computer, and a spark jumped from my finger to the
metal bottom housing of the Apple. It didn't show any
signs of a problem, but when I tried typing it didn't
work. No input, no output. I fiddled with Kermit,
checked connections, etc. Nothing. I looped back the
Apple to itself and got nothing. Replacing a 1488 (or
89, don't remember, they were socketed, I just tried
one, then the other) on the Super Serial Card got the
Apple working again, but it wouldn't talk to the PC.
Moved it to the other serial port on the PC and it
worked. Looking at the logic board on the PC revealed
an RS232 tranciever chip (forget the part number off
the top of my head) with a burnt hole in it. Of
course, being modern PC crap, this chip is surface
mount, with extremely tiny leads. And this is why my
PC now no longer has ttyS0.
I'd probably have a go at replacing it. SMD stuff worried me the first time
I had to repalce it, after I'd changed the part I wondered what all the
fuss was about. The tirck I've found it nto to worry about solder bridges
when you're fitting the new chip, but then to clean them up later with
soldawick (or whatever you call it).
-tony