Remove either one of the lamp terminals (brown or green) from the amplifier unit and test the lamp for continuity with the aid of a tester. If no continuity is determined, it is an indication of a lamp blow-out, necessitating lamp replacement.
Install the battery, set the SW-3 to "ON" position and check the voltage of (T11) to (T1). If the voltage is determined to be about the same level as that of the power source, it is an indication of either an improper contact of the 1K ohm VR or a malfunction of the transistors.
In this case, check the soldered ends of the 1K ohm VR. If both the soldered sections are found to be in order, replace the amplifier unit.
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.
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.
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.
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.
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.
Remove one of the terminals of the "OVER" (or "UNDER") indicator lamp and undertake continuity test. If no continuity is determined, make replacement of the lamp.
If the indicator lamps are found to be in order, it is an indication of a malfunction of the transistors of the amplifier unit, necessitating replacement of the unit.
This malfunction can be attributed to excessive rise in the electric potential of (T5)-(T1) due to either shortcircuiting of the CdS or failure of the BALANCING resistor (VR-1) to provide normal function. Normally, the voltage at (T5)-(T1) should be within the range of 0.6V and 1.0V at the point where both lamps turn off.
Because shortcircuiting of the CdS itself is quite improbable, check whether or not the CdS baseplate is shortcircuited.
Remove the blue lead wire of the amplifier unit on the CdS baseplate, apply the tester rods between the colored patterns and undertake continuity test.
When the lens aperture is set manually to f/5.6 and a light emitted by a standard light source is directed, each CdS should give the following resistance value (The reading should be approximately half this figure in case measurement is taken of both CdS cells simultaneously):
| BLV 7 | 60 - 160K ohm | ||
| BLV 11 | 10 - 20K ohm | ||
| BLV 15 | 1.35 - 3.5K ohm | ||
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Remove the blue lead wire of the VR-1 from the CdS baseplate and measure the resistance value of the VR-1. In this case, the resistance reading should be within the allowable limit specified in the chart given in Fig 4.2.3.1 [above].
In case the voltage at (T5)-(T1) is determined to be normal, the cause can be attributed to malfunction of the transistors, in which case the amplifier unit must be replaced.
This is due to either a decline in (T5)-(T1) voltage to almost 0V caused by shortcircuiting of the VR-1 or failure of the CdS to provide normal resistance, or malfunction of the amplifier unit.
Undertake continuity test according to procedure outlined in 4.2.3.1. The resistance reading in this case should also correspond to that given in the same paragraph. If the resistance is found to be excessive, remove one CdS cell at a time and check their resistance individually. The resistance reading in this case should be within the allowable limit specified in Fig. 2.3.1.
Make through check according to procedure outlined in 4.2.3.2.
Adjustment of the exposure readout circuit consists of either one of the following two methods:
One method consists of loosening the two screws on top of the slide resistor assembly and turning to offset resistor ring to alter its position in relation with the brush. This method (providing a balanced shifting of the offset resistor characteristics) enables precise regulation of the 'light turn-off point' without altering the 'light turn-off range'. The other consists of adjustment of the 30K semi-fixed resistor incorporated in the amplifier unit. This provides effective regulation of the 'light turn-off point' of the "OVER" indicator lamp.
- The 'light turn-off' position generally tends to shift toward a
direction providing under-exposure at all light levels.
This malfunction is caused when the resistance of the offset resistor (VR-1) rises to a level beyond the standard reading. To repair, turn the offset resistor ring in a left motion to effect a balanced shifting of the resistor characteristics. - The 'light turn-off' position generally tends to shift toward a
direction providing over-exposure at all light levels.
This malfunction is caused when the resistance of the BALANCING resistor (VR-1) declines below the standard level. To make adjustment, turn the offset resistor ring in a right motion.
- Excessively wide 'light turn-off range'.
This can be attributed to adjustment of the 'light turn-off range' adjustment resistor (30K ohm VR) to a resistance reading below the normal level. To repair, turn the resistor in a left motion with the aid of a screw-driver to a setting that provides higher resistance. - The 'light turn-off' position generally tends to shift toward a
direction providing over-exposure at all light levels.
This malfunction is caused when the resistance of the BALANCING resistor (VR-1) declines below the standard level. To make adjustment, turn the offset resistor ring in a right motion.
In this case, the SW-2 fails to turn on. When using a DC voltage stabilzer, a flow of electric current to the extent of about 30ma (at 5.5V) should be determined at the time the shutter is released. Poor contact of the SW-2 is caused occasionally by accumulation of dust or other foreign particles. To repair, therefore, wipe and clean the contact pieces meticulously.
Remove the black lead wire and undertake continuity test on the electro-magnet. The resistance value should be approximately 270 ohms (with both electro-magnets).
This can be attributed to either shortcircuiting of the shutter printed wiring panel or shortcircuiting within the VR-2. In this case, remove the yellow or pink lead wire and check the insulating resistance between the colored patterns. Also, undertake continuity test of the VR-2.
The resistance of the VR-2 should be within the limit specified in Fig. 2.2.2.
If everything is found to be in order after undertaking [the] thorough check outlined in the preceeding three paragraphs, the cause can be pinpointed on malfunction of the transistors, in which case the amplifier unit must be replaced.
The shutter sectors remain open at "B" setting even after pressure on the shutter release button is released. This is attributed to the fact that the electric potential of the charging condenser (C1) fails to rise because either the shutter speed resistor (VR-2) or the trigger switch (SW-5) does not reset to the "OFF" position.
Check the resistance of the VR-2 according to the procedure outlined in 4.3.1.3. If no continutiy is determined, it is an indication of a disconnection of the yellow or pink lead wire or poor contact of the contact pieces of the VR-2.
Remove the gray lead wire from the shutter printed wiring panel and undertake continuity test by setting the shutter to the "B" setting.
This test must be undertaken by setting the shutter control to either "B" or slow shutter speed setting, because the SW-5 sets to "OFF" position only over the duration the shutter remains open.
If it fails to set to "OFF" position, it is an indication of a malfunction of the SW-5; therefore, make proper adjustment of its contact pieces. Because the position at which the SW-5 sets to "OFF" position directly affects the exposure time (particularly in case of high shutter speeds), the precise position where it turns off must be checked meticulously after adjusting the contact pieces.
If the shutter speed resistor and trigger switch are found to be in order, the cause can be attributed to malfunction of the transistors, causing the shutter to remain open because no electric current flows to the electro-magnet even if charging of the condenser (C1) takes place. To repair, make replacement of the amplifier unit.
Undertake necessary check because this can be attributed to poor contact of the Bulb switch (SW-6) or poor contact between the Bulb resistor of the VR-2 and the contact piece.
Specifically, this malfunction consists of the shutter closing automatically at "B" setting while the shutter release button is being depressed or of the shutter functioning at speeds faster than the normal at slow speeds (ranging from 1/8 to 1 sec.).
This is caused by improper insulation between the plus (pink) circuit and the "Bulb" resistor incorporated in the shutter speed resistor (VR-2) as well as the brown lead wire circuit.
After adjusting the shutter speed control dial to 1/1000 sec. setting, check the insulating resistance of both terminals of the "Bulb" switch (SW-6) with the aid of an insulating resistance meter. The reading in this case should be 100 megohms or more.
The points where poor insulation may be caused most commonly are:
- Soldered sections of the lead wires of the "Bulb" switch (SW-6) or improper adjustment of the position of the contact pieces.
- Soldered sections of the lead wires of the shutter speed resistor (VR-2).
- Poor insulation of the "Bulb" resistor.
There are times where the shutter functions at about 8ms [1/125 sec.] continuously or once in about ten times.
This is caused because the shutter power switch (SW-2) is not held properly. In other words, the SW-2 (red and pink) is shortcircuited on the shutter printed wiring panel. If, after operating the shutter about twenty times, it provides normal function, it is an indication that the activating lever of the SW-2 fails to hold the power switch-off lever. In this case, replacement of the shutter is required.
In case the shutter functions either excessively fast or slow at all shutter speeds, proper adjustment can be accomplished by turning the shutter speed resistor ring in the required direction.
The adjustment screw on the base of the slide resistor assembly is linked directly to the shutter speed resistor ring. By loosening this screw and turning it either to the left or right along the guide slot, proper adjustment can be made.
This is caused when the resistance of the shutter speed resistor (VR-2) is set below the normal level. Proper adjustment can be made by shifting the resistor in the direction to the right of the main spindle when viewed from the bottom of the resistor itself.
This is caused when the resistance of the VR-2 is set beyond the normal level. To make proper adjustment, turn the resistor ring in a left motion.
Because this can be attributed most commonly to the characteristics of the shutter speed resistor (VR-2), check the resistance according to the procedure given in 4.3.1.3.
In case it is determined that the resistor fails to provide the normal characteristics, replacement of the resistor is required because there is no effective means of adjustment.