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When I received this Friden 1217 it was operational for a short while, but soon started to block during calculations.  After quite an extensive search I discovered a loose slotted screw inside the the machine at a point which couldn’t  possibly be reached with a screw driver.

However, using a small screwdriver as a chisel, sticking it in the slot I managed to fasten the screw.  Beforehand I cleaned the screw and its surroundings and put some glue on it. Until today it holds.

Fortunately it works fine,  so there is no need to check the 81 !! adjustments described in a separate adjustment manual.

This machine runs at two speeds, one for control actions and a higher speed for addition and subtraction in calculations.  Photo’s A show the two switches.

The cover of the machine can be very easily removed by loosing two screw a single turn and then loosen two clips which hold the cover.

(See photo’s B)

Spark suppression:

Many, perhaps most machines suffer from leaking or removed capacitors.  In this machine they were partly removed. From what was left I wasn’t sure how the circuit originally was built.  I rebuilt it in order to obtain a proper spark suppression, but guess that originally less components were used.

B: Case mounting clip

Result register with carry mechanism

A: The speed regulator contains two switches which open at different speeds