Service Manual

Foreword
This manual contains matters necessary for repair and servicing of the Yashica TL
Electro-X.
The Yashica TL Electro-X incorporates the following functional features which make it
completely different from other focal shutter single-lens reflex cameras:
1. Thru-the-lens exposure readout system which does not require an exposure meter and
provides measurement of the correct exposure at stopped-down aperture through
preselection of either the lens aperture or shutter speed.
2. Electronic-controlled focal plane shutter affording an infinite range of intermediate
shutter speeds (and providing faithful function at 1/1000 sec. even when battery power is
exhausted).
Its exposure readout and electronic shutter systems follow the pattern of those featured in
the Lynx-5000E (14E) and Electro 35, and their merits are outlined in their respective
repair manuals. Generally speaking, therefore, the Yashica TL Electro-X can be said to
be an equipment which offer all advantanges of the above-mentioned cameras.
Principles of operation
The circuitry of the Yashica TL Electo-X can be generally classified into the exposure
readout circuit, shutter circuit and battery checker circuit. The exposure readout circuit
and the shutter circuits are linked to each other with the aid of a slide resistor.
A coaxial dual variable resistor is employed for this purpose. Its top section forms the
balancing resistor (VR-1), while its bottom section functions as the shutter speed resistor
(VR-2).
The circuit pattern consists of a combination of the exposure readout circuit of the Lynx-
5000E (14E) and the shutter circuit of the Electro 35, and correlation between the
functions of these two circuits is maintained through incorporation of the variable
resistor.
1.1 Exposure Readout Circuit
The intensity of the light controlled by means of the diaphragm (exposure reading
through stopped-down) is sensed by the two CdS sensors incorporated in the pentaprism
housing on both sides of the viewfinder eyepiece.
Being a photoconductive cell, the CdS serves to vary the resistance value at a ratio
inversely proportional to the intensity of light to which it is exposed.