NetNews Usenet Archive 1992 #31/NN_1992_31.iso/spool/comp/os/cpm/1509

Internet Message Format | 1992-12-22 | 1.6 KB

Path: sparky!uunet!tron!news.pgh.wec.com!godel!oscsf
From: [e-mail] (Chuck Fuller)
Newsgroups: comp.os.cpm
Subject: Kaypro blowing fuses - hardware advice needed
Date: 22 Dec 1992 14:18:51 GMT
Organization: Westinghouse Corporate Computer Services
Lines: 28
Distribution: world
Message-ID: <[e-mail]>
NNTP-Posting-Host: godel.pgh.wec.com
Originator: oscsf@godel

My trusty pre-'83 Kaypro II (which, by the way, was under 18 feet of
acidic, muddy flood water for a couple of days in '85) blew a fuse
mid-session the other day.  Of course, a replacement fuse blew
immediately upon power-up.  Being more oriented toward the software end
of the computing world (but having some basic understanding of how the
hardware works), I appeal to the Kaypro hardware gurus for advice on where
to begin my diagnosis, probable causes, etc.

One point bears mentioning:  the machine currently has two half-height
drives squeezed into the top half of the drive cage, leaving the bottom
half open at the front.  I _think_ I saw sparks through this opening
when the first fuse blew, but I can't be certain.  There were no visible
sparks on power-up with the replacement fuse.

Examination of the motherboard and power supply show a little rust on
the solder but no obvious "burned" spots.  There appear to be no "rust
bridges" in the layout.  The only thing that I've noticed that seems
questionable is a small, blackened spot at the top of C1 on the power
supply.

I'd appreciate any suggestions that you can provide.

A note to Jay Sage: keep those spare parts handy!

Thanks ...
- Chuck
spots.