Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!att!cbnewsj!cbnewsi!rte
From: rte@cbnewsi.att.com (ralph.t.edwards)
Newsgroups: comp.sys.mac.hardware
Subject: Serial ports zapped by lightning?
Keywords: Lightning Fix How
Message-ID: <1991Jan30.153900.12842@cbnewsi.att.com>
Date: 30 Jan 91 15:39:00 GMT
Organization: AT&T Bell Laboratories
Lines: 24

Last year lightning zapped my house, probably through the power line,
several pieces of electronics croaked, but not (I thought) the
computers, which were on surge arresters.  The modem was not on the
same surge arrester as the computer (not enough plugs) and was zapped.
It was still under warranty, so I got it fixed.
The fix was a transister like object near the AC input.
But, although the modem works fine on other computers,
it does not work with my plus, to which it was attached at the great zapping.
So, here are the questions:

1. Both serial ports work with the printer, neither see the modem.
What lines are used by the modem that aren't used with the printer?

2. What symptoms should I look for with my RS-232 tester?

3. If I conlude that the ports are zapped, can one or two ICs
be replaced, and where are they?

4. I haven't opened up the plus yet, although I plan to soon.
It's 13 months old.  Do they use surface mounts or what?

I'm a reasonably competent tinkerer, and have opened my older mac
several times to fix problems, add upgrades etc.
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