Section III. LENSES
MALFUNCTION | PROBABLE CAUSE | REMEDY |
Fits too loosely in camera | 35mm Lens (fig. 42) Damaged bayonet mounting lugs Locking slot damaged | Replace helical focusing assembly (25) Replace helical focusing assembly (25) |
Fits too tightly in camera | Damaged bayonet mounting lugs Burrs on base of lens or bayonet mounting lugs | Replace helical focusing assembly (25) Remove burrs by honing |
Positions other than 35mm bright-line frame | Bayonet lug engaging frame selector damaged Locking slot damaged | Replace helical focusing assembly (25) Replace helical focusing assembly (25) |
Rangefinder image jumps when focusing lens | Burrs on rangefinder cam of helical focusing assembly (25) | Remove burrs by honing |
Rangefinder images do not coincide at infinity | Damaged bayonet mounting lugs Burrs on base of lens | Replace helical focusing assembly (25) Remove burrs by honing |
Focusing ring can be rotated without focusing lens | Loose retaining ring (19) | Tighten retaining ring |
Incorrect f/stop indexing | Loose retaining ring (5) Loose retaining ring (10) | Tighten retaining ring Tighten retaining ring |
Buckled diaphragm blades | Dirty diaphragm blades Damaged diaphragm blade | Clean diaphragm blades Replace damaged diaphragm blade |
Fits too loosely in camera | 50mm Lens (fig. 43, 44) Damaged bayonet mounting lugs Locking slot damaged | Replace helical focusing assembly (6). fig. 44 Replace helical focusing assembly (6) |
The photographic effects of lens malfunctions are listed in TM 11-6720-244-12, paragraph 4-8. Mechanical malfunctions are detailed in paragraph b below.
a. Malfunctions. Mechanical malfunctions are generally obvious. Poor optical performance may require photographic testing to establish the cause. All lenses should be checked photographically after being repaired.
b. Troubleshooting Chart.
MALFUNCTION Fits too tightly in camera | PROBABLE CAUSE Damaged bayonet mounting lugs Burrs on base of lens or bayonet mounting lugs | REMEDY Replace helical focusing assembly (6) Remove burrs by honing |
Positions other than 50mm bright-line frame | Bayonet lug engaging frame selector damaged Locking slot damaged | Replace helical focusing assembly (6) Replace helical focusing assembly (6) |
Rangefinder image jumps when focusing lens | Burrs on rangefinder cam of helical focusing assembly (6) | Remove burrs by honing |
Rangefinder images do not coincide at infinity | Damaged bayonet mounting lugs Burrs on base of lens | Replace helical focusing assembly (6) Replace burrs by honing |
Focusing ring can be rotated without focusing lens | Loose retaining ring (16), fig. 43 | Tighten retaining ring |
Incorrect f/stop indexing | Loose set screw (4) Loose set screws (6) | Tighten set screw Tighten set screws |
Buckled diaphragm blades | Dirty diaphragm blades (12) Damaged diaphragm blade (12) | Clean diaphragm blades Replace damaged diaphragm blade |
Fits too loosely in camera | 135mm Lens (fig. 46, 47, 48) Damaged bayonet mounting lugs Locking slot damaged | Replace bayonet ring (3). fig. 47 Replace bayonet ring (3) |
Fits too tightly in camera | Damaged bayonet mounting lugs Burrs on base of bayonet ring or mounting lugs | Replace bayonet ring (3) Remove burrs by honing |
Positions other than 90mm bright-line frame | Bayonet lug engaging frame selector damaged Locking slot damaged | Replace bayonet ring (3) Replace bayonet ring (3) |
Rangefinder images do not coincide at infinity | Damaged bayonet mounting lugs Burrs on base of bayonet ring Loose screws (2) Bent coupling in differential cam assembly (8) Viewing unit incorrectly collimated (fig. 48) | Replace bayonet ring (3) Remove burrs by honing Tighten screws Straighten to 6.5mm from base of bayonet ring (3) Collimate viewing unit |
Incorrect f/stop indexing | Loose set screws (9), fig. 46 Loose set screw (13) | Tighten screws Tighten screw |
Buckled diaphragm blades | Dirty diaphragm blades (20) Damaged diaphragm blade (20) | Clean diaphragm blades Replace damaged diaphragm blade |
Section IV. FLASH UNIT
Reflector wont open | Defective segment cleat | Replace cleat |
Reflector wont close | Segments damaged or bent cleat | Replace damaged segment or cleat |
Reflector will not lock in open position | Upper segment damaged Lower segment damaged | Replace segment Replace segment |
Reflector handle loose or tight in mounting bracket | Mounting bracket damaged Pressure spring damaged | Repair or replace bracket Replace pressure spring |
Bayonet-base bulb will not stay in socket | Spring broken or weak | Replace spring |
Bayonet-base flash bulbs will not eject | Release spring too tight Contact spring broken | Adjust spring Replace spring |
Mounting foot loose | Loose or missing screws Bottom block broken | Tighten or replace screws Replace bottom block |
Flash bulb fires when inserted in socket | Connecting cord shorted Shorted resistor | Replace connecting cord Replace resistor |
Flash bulb will not fire | Battery reversed Battery exhausted Connecting cord open Capacitor defective Rectifier defective | Reverse polarity Replace battery Replace connecting cord Replace capacitor Replace rectifier |
Capacitor will not charge | Defective capacitor Defective resistor Battery exhausted | Replace capacitor Replace resistor Replace battery |
The photographic effects of flash unit malfunctions are listed in the troubleshooting chart (par. 4-8) of the KS-15(4) Operators Manual TM 11-6720-244-12.
a. Mechanical malfunctions are generally obvious and their remedy self-evident.
b. Electrical malfunctions usually require checking with a multimeter. The procedures are outlined in paragraph 5-3c of TM 11-6720-244-12.
c. Troubleshooting Chart. MALFUNCTION PROBABLE CAUSE REMEDY
