circuit or component failures occur, the Block Diagram is useful
for isolating the problem to a particular circuit.
Q.4.1
Type 1 Faults
If any Type 1 Fault Detection circuit on the LED Board senses a
fault, OR gate U32 provides a logic HIGH output. If the output
of U32 goes HIGH, or if a Type 2 fault repeats when the
transmitter cycles back ON, U19-8 goes logic HIGH. Pulse
stretcher and OR gate U70A ensure that a “Type 1 Fault-H” to
the Controller section turns the transmitter OFF and prevents the
transmitter from turning back ON for approximately 1 second or
for as long as the Type 1 Fault is still present.
“RESET A” and “RESET B” inputs to Type 1 Fault logic reset
the LED indicators on the ColorStat™ panel. The fault detection
circuits clear and remove the “Fault-H” output when the Fault is
cleared; they do not clear the fault indication on the ColorStat™
panel. Clearing the fault will not reset the status indication; the
RESET button on the ColorStat™ panel must be depressed, or a
TYPE 1 TURNS PA POWER SUPPLY OFF (Manual Restart Required)
EXT External Interlock
AIR Air Flow Fault
DOOR Door Interlock
SUPPLY FAULT PA Power Supply Protection
OVER VOLTAGE PA Power Supply Overvoltage Protection
CABLE INTERLOCK Modulation and Driver Encoder Cables
B+ DC Regulator B+ Regulated Fault
B- DC Regulator B- Regulator Fault
+5V Output Monitor +5V on board Regulator Fault
+15V Output Monitor +15V on board Regulator Fault
REPEATING TYPE 2 FAULT See NOTE below
TYPE 2 TURNS PA POWER SUPPLY OFF (Recycles Back ON)
UNDER DRIVE RF Drive Level to PA LOW
OVER DRIVE RF Drive Level to PA HIGH
OVER CURRENT * PA Power Supply +230 Vdc Overload
* Transmitter will attempt to limit current first, then shut off high voltage if limiting is not sufficient.
NOTE: If Type 2 fault condition is still present when the transmitter cycles back on,or repeats within 2.4 seconds after the
transmitter cycles back on, it becomes a Type 1 fault and will require a manual restart.
TYPE 3 LOWER POWER OUTPUT
BANDPASS VSWR Output Monitor detects sucessive VSWR’s
ANT. VSWR Output Monitor detects sucessive VSWR’s
TEMPERATURE Driver Encoder/Temp Sensor detects an over temperature condition
TYPE 4 PA TURN OFF ONLY (PA Kill only, High Voltage Remains ON)
BANDPASS VSWR Output Monitor detects one shot VSWR
ANT. VSWR Output Monitor detects one shot VSWR
+15V A/D Converter on board +15V Regulator Fault
-15V A/D Converter on board -15V Regulator Fault
+5V A/D Converter on board +5V Regulator Fault
+15V Analog Input on board +15V Regulator Fault
-15V Analog Input on board -15V Regulator Fault
TYPE 5 CLEAR MODULATOR DIGITAL AUDIO DATA
CONVERSION ERROR A/D Converter
TYPE 6 FAULT DISPLAY ONLY
RF AMP PA RF Amplifier Fuse Blown
Table Q-1. DX 25U Fault Types
DX-25U
Q-2 888-2297-002 Rev. R: 11-11-96
WARNING: Disconnect primary power prior to servicing.
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