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7-1
Step
1
Verify that the low voltage power supply, +5 volt, is present at the
regulator Q4 of the 2285 card. If not, determine fault and repair.
2
Verify supply voltage of +24 volts at plus (+) side of C8 of the 2285
card. If not, determine fault and repair.
3
Verify quadrature of the shutter encoder's phase A and phase B outputs:
a.
b.
4
Verify the reference frequency at TP33 of the 2293 card.
This square wave should have a frequency of 192 KHz. If
not, determine wiring fault or defective 2293 card; repair or
replace.
5
Disconnect J2 from the 2285 card and measure the
resistance from J2 pin 4 to J2 pin 3. This should be the
shutter motor armature, and should measure about one
ohm. Reconnect J2. Determine wiring fault or defective
motor; repair or replace.
7-2
Step
1
This may indicate worn brushes in the Shutter motor. Replace brushes
or motor.
2
Erratic Shutter movement may also be caused by an unstable 192-KHz
reference from the 2293 card. If required, adjust R20, the phase-locked
loop circuit, on the 2293 card. Note that this adjustment will have no
effect if running in crystal lock mode.
CHRISTIE INC. - - 35/70 Service/PM Manual
CHRISTIE INC.
July, 1997
READY DIAGNOSTIC TABLE
Shutter Failure –
CONDITION 1: Shutter is at speed when phase A and phase B are measured to
be 600 Hz at U29 pins 23 and 24 of the 2293 card. The shutter index pulse at U37
pin 18 of the 2293 card should measure 60 Hz. (Note: speed referenced to 60FPS
operation.) If this is not the case:
If shutter is moving, connect dual trace oscilloscope to pins 23
and 24 of U29 on the 2293 card and verify quadrature. If signals
are not present or are not in quadrature, determine wiring fault or
defective encoder and repair or replace.
If shutter is not moving, continue to step 4.
Table 7.8: READY Diagnostic Table (Continued)
READY DIAGNOSTIC TABLE
Shutter Failure –
CONDITION 2: The Shutter movement is erratic; a sound is heard that indicates
the Shutter is hunting.
Table 7.8: READY Diagnostic Table (Continued)
7 : T r o u b l e s h o o t i n g G u i d e
Diagnostic
Diagnostic
Result
Result
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