On 2024-12-23 05:11, Nico de Jong via cctalk wrote:
When I was an operator, we once had a visit from a CE who had to
repair the carriage control mechanism. In order to do that, he had to
use a big screwdriver, and of course he lost it. It hit the 1403 N1's
power supply, blew all fuses. This was not enough; the screwdrive hit
obviously the plus and minus pole of the main capacitor (it's about 55
years ago), so the current was so large that, after the things had
cooled down, he could lift the capactor out of the printer just by
lifting the screwdriver
It was by the way the same CE that got his tie wrapped up in the print
chain....
The same company once had a bunch of visitors who were allowed to
visit the machine room, which normally was a bit nono. One of the
guests took his coffeecup with him, put it on top of the 1403, and
while things were explained to the crowd, the cover lifted and ....
well you can guess the rest. He was quite pisssed off, but it was his
own fault
Another thing I'll never forget, was the 2540. It had 5 bins, and the
middle one could be used for accepting read cards and punched cards.
Once an operated started to read cards while cards were being punched,
and both routines used the middle bin. That is not to be recommended !
/Nico
My experience with a capacitor occurred early in my time as a CE.
Before the days of switching regulators IBM used a lot of power supplied
that where regulated by a resonant winding on the input transformer. If
the capacitor on that winding goes short you get no output from the
transformer. I was working on a banking terminal that had no power.
Where I was working I was behind a row of machines and cabinets for
things like signature cards, in a narrow isle against the windows, so no
one in the branch could see me. I had already been caught once by a
shorted resonant capacitor so first thing I did pop off one of the leads
to the capacitor and sure enough it powered up, but I didn't leave it at
that I started to second guess it so I turned off the machine and
reattached the wire to the capacitor, and it powered up again. Then I
started thinking that it probably went short due to heating up, so I
thought it best to leave it disconnected until I could get a
replacement, the machine would work fine without it for a day or two.
It was then that I made the mistake, I thought I should discharge the
capacitor, so I shorted the leads with the shank of a screwdriver and
there was a load crack and a bright flash and next thing some of the
banks staff where looking over the machine and asking if I was OK. I
still have that screwdriver some 45 years later.
You quickly learned to tuck in you tie and roll up your sleeves not just
to keep them out of the mechanisms, but also to keep them out of the oil
and grease. The worst things I worked on for getting dirty was proof
machines. The endorsers used a purple indelible ink and they would get
gummed up with a mixture of ink and paper dust and working with gloves
was impossible so you would end up with your hands stained purple.
Later someone stumbled on the idea of using a ultrasonic cleaner which
we could use to clean everything except the endorsement plate, the
ultrasonic cleaner would cause the endorsement plate to delaminate, but
it was easy to clean by hand.
Paul.
