Service Manual

4.1.2 Improper voltage range.
The battery checker lamp should normally turn on at a voltage range of over 3.8V and not
exceeding 4.2V under a temperature of 25°C. Since the battery checker circuit has a
temperature characteristics of -0.1V/+10°C when a temperature of 25°C is taken as a
standard, due consideration must be given to adjustment of the voltage range in
accordance with the temperature of the room in which the measurement is being taken.
For instance, under a temperature of 15°C, the voltage range will be 0.1V over the
standard 25°C and will therefore be over 3.9V and not exceeding 4.3V. On the other
hand, the voltage range will be over 3.7V and not exceeding 4.1V at a room temperature
of 35°C.
4.1.2.1 Lighting voltage exceeds 4.2V.
This is attributed to improper adjustment of the battery checker voltage regulating resistor
(1K ohm VR), providing a resistance which is beyond the normal level. To repair, turn
the adjustment screw of the VR in a right motion and reduce the resistance to an
appropriate level.
4.1.2.2 Lighting voltage falls short of 3.8V
This is due to excessively low resistance of the 1K ohm VR. To repair, turn the
adjustment screw of the VR in a left motion and increase the resistance.
4.2 Malfunction of the exposure readout circuit
4.2.1 Both the "OVER" and "UNDER" indicator lamps fail to turn on.
4.2.1.1 Malfunction of the exposure readout switch (SW-1).
Test the SW-1 for continuity. Set the tester rods between the red and orange patterns of
the CdS baseplate and turn on the exposure readout activator switch. In case no
continuity is determined, it is an indication of either disconnection of the wiring,
improper adjustment of the switch contact pieces or accumulation of dust or other foreign
particles within the switch. To repair, check the wiring and clean the contact pieces of the
switch.
4.2.1.2 Malfunction of the amplifier unit.
If both the "OVER" and "UNDER" indicator lamps are found to be in normal working
condition and malfunction outlined in 4.2.1.1 cannot be determined, it is an indication of
a malfunction of the transistors featured in the unit. In such a case the entire unit must be
replaced.
4.2.2 "UNDER" indicator lamp turns on normally, but "OVER" lamp fails to
light, or "OVER" lamp functions normally, but "UNDER" lamp fails to turn on.