Philips Vari-Lite VL770, Service Manual

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VARI
❋
LITE - VL440 / VL770 / VL880 S
POT
L
UMINAIRES
S
ERVICE
M
ANUAL
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Testing
Luminaire Self-Tests
The luminaire is capable of running self tests by using the TEST menu functions. For detailed
instructions regarding the luminaire’s self-test function, refer to the VL440 / VL770 / VL880 Spot
Luminaires User’s Manual (02.9687.0001).
Calibration Sequence
When the luminaire is powered up for the first time, the default setting is enabled and the lamp will
remain off. When AC power is applied, the luminaire will immediately begin a calibration sequence
that steps it through full pan and tilt movements. The internal color and beam mechanisms will also
move through a full range of motion. After calibration, the luminaire head will either stop at its "home"
position (which positions the pan axis at mid-rotation and the head parallel to the yoke with the lens
pointing away from the luminaire enclosure) or move to its current DMX-defined position if DMX
data is present. All internal mechanisms also move to their "home" or DMX-defined positions.
CAUTION: Before applying power, be sure the luminaire is hung (or positioned), and the service tilt
and pan locks are disengaged, so that the head and yoke can move freely without restriction.
Sensor Testing
Most mechanisms within the VL440 / VL770 / VL880 luminaire are equipped with either optical or
magnetic sensors. The VL440 / VL770 / VL880 master control board (MCB) has labeled test points for
reading DC voltages at each sensor. Testing is best performed with a digital voltmeter for sensor
readings or an Oscilloscope for pan/tilt encoder readings. The values can be used to determine whether
a circuit is opening correctly or needs further troubleshooting.
Guidelines:
• The values will change depending on whether the sensor reading is Open or Closed.
• The values will be different depending on the type of sensor: optical or magnetic.
• As a general rule, if a change occurs from 5v to 0v or visa versa, then it is working.
• An Open reading occurs when the sensor is not aligned - tab not at sensor (typically a non-zero
DMX value).
• A Closed reading occurs when the sensor is aligned -tab in or at sensor (typically a zero DMX
value).
• Optical sensors read high when the sensor is Closed.
• Magnetic sensors read Low when the sensor is Closed.
• High value - 5 volts (typically 4.9 volts).
• Low value - 0 volts, or up to approximately 0.2 volts.
Notes regarding specific mechanisms:
• Tilt sensor reads high when the tab is in the sensor. The mechanism calibrates to the edge and its
tab covers 50% of travel. Pan and tilt encoders are best read with a scope to read the encoder ticks.