6 Aug
2000
6 Aug
'00
7:07 a.m.
On 2000/08/06 at 12:19pm -0400, Christian Fandt wrote:
However, during a production day, that old
"A" developed a shorted
series-pass transistor in its switching PSU board which put ~+18 volts onto
the +5 V supply bus. Well, you know what happened next. I recall very well
the HP Service Manager down at the old Paramus, NJ Service Center grousing
that this happened occasionally and that those %$@*)! designers did not put
in a crowbar circuit or other protection to prevent smoking the whole
machine.
Is there a straightforward fix for this? I'm not up to tracing out the
supply and developing one myself, but I could follow instructions if
someone else has done this already.
Regarding the comment by someone in this thread (at
8:08 AM, 3 Aug as shown
above), what makes the replacement kybd so horrible?
The keys tend to bind unless they are pressed exactly in the center and
exactly in line with the stroke, and they bottom out hard.
Could that have been
an early version of a replacement before the Cherry's were used?
I don't think this one is a *replacement* keyboard -- the date stamped on
the keyboard (22 Aug 1979) is earlier than the date on the bottom of the
case (5 Feb 1980). There is no obvious sign that the keyboard was made by
anyone other than HP; the PCB is marked on the top upper left corner with
[(hp)] 88809F REV A 5021-1416
--
Kevin Schoedel
schoedel(a)kw.igs.net