Checking The Trigger/Memory Switch - Minolta XD-11 Repair Manual

to ground should turn on the LEDs.
If the LEDs turn on during your short­
ing test, the problem must be in the
metering switch. However, if the LEDs
still w o n 't turn on, the problem is in the
circuit. Suppose, for example, that you
measure OV to pin 1 of IC1 while you're
shorting the green wire
Suspect a problem with H-IC; transistor
T1, apparently isn't turning on.
Use similar techniques to check the
release switch. But remember — the
release switch only closes at the elec­
tronically controlled speeds. Use any
speed-knob setting except bulb or the
mechanical 1/100 second. Then measure
the voltage to the orange-wire connec­
tion, Fig. 39. You should measure 2.5V
until you fully depress the release button;
the voltage should drop to 0V with the
release button depressed.
You can also use a shorting test to check
the release switch. Shorting the orange wire
to ground should release the shutter. If your
shorting test doesn't release the shutter, IC2
may be the problem.
CHECKING THE TRIGGER SWITCH
Like the electromagnet, the trigger
switch is a shutter part. The trigger
switch should close when you cock the
shutter. When the shutter releases, the
trigger switch should open to initiate the
exposure.
If the trigger switch remains closed, the
shutter will hang open. If the trigger
switch fails to close or makes poor con­
tact, you w o n 't be able to bring in your
Figure 40
shutter-speed adjustments — especially
the fast speeds. Erratic shutter speeds may
also result from poor contact in the trigger
switch.
the black wire. Fig. 39, and ground. Check
the continuity between the black wire and
to ground. ground with the shutter cocked; you
should
dicating that the trigger switch is closed.
Then release the shutter. You should now
measure no continuity — an open — be­
tween the black wire and ground.
CHECKING THE MEMORY SWITCH
mally causes the shutter to hang open.
W ith most cameras, you must perform
major surgery to reach the memory switch.
But, in the XD-11, you need only remove
the top cover to clean the memory switch
and check the continuity.
closer to the back of the camera connects
to the memory capacitor and to pin 10 of
IC1, Fig. 34. You can check the memory
switch by measuring the voltage to pin 10
w ith the release button partially depress­
ed; you should measure around 0.5V. If
the memory switch isn't making good
contact, you'll measure 0V at pin 10.
tween the front blade of the memory
switch, Fig. 33, and the memory ca­
pacitor, Fig. 35. You should measure
direct continuity. W ith the shutter held
open on bulb, you should measure no
continuity.
The trigger switch connects between
measure direct continuity,
Poor contact in the memory switch nor­
The blade of the memory switch that's
Or you can measure the continuity be­
in­