Specifications

M.6 Troubleshooting
NOTE
Before troubleshooting the Controller it is suggested that the
back up batteries be removed from the Transmitter Interface.
Before removing any components from the board, it is also sug-
gested that the Capacitor backup be discharged by grounding
TP16. Failure to do so could result in short battery life and
failure of components.
Due to the nature of PAL operation this troubleshooting proce-
dure is grouped by symptom of problem and then list some steps
that will help in determining which PAL or pair of PALs may be
defective. Refer to the Controller Schematic (839-7930-021) as
needed.
M.6.1
LED Observation
The first step in troubleshooting a Controller problem is to put
CB3 on the Power Supply Status Panel in the STANDBY
position and observe the LEDs on the board.
a. DS5 and DS6 should be illuminated GREEN indicating
both +5VDC power supplies are active.
b. DS1 through DS4 should be illuminated GREEN indicat-
ing that there are no faults inhibiting turn-on and all four
PALs are operational.
M.6.1.1 Troubleshooting The Power Supplies
There are duplicate +5VDC power supplies on this board, if
either supply is not present a Controller Supply Fault will be
visible on the Control front panel. A non-illuminated DS5 or
DS6 means that supply is faulty, begin by checking the fuse for
RF MUTE Faults
OSCILLATOR FAULT OSC.RF.X
BUFFER AMP FAULT BR.RF.X
PREDRIVER FAULT PR.RF.X
OUTPUT MONITOR NETWORK VSWR OM.ON.X
OUTPUT MONITOR ANTENNA VSWR OM.AV.X
OUTPUT MONITOR SUPPLY FAULT OM.SF.X
ANALOG INPUT SUPPLY FAULT AI.SF.X
A/D SUPPLY FAULT AD.SF.X
A/D CONVERSION ERROR AD.CE.X
Foldback Faults
NETWORK VSWR OM.ON.X
ANTENNA VSWR OM.AV.X
AIR FLOW REDUCED AF.R.X
OVERTEMP FOLDBACK OT.FB.X
A/C Restart Faults
AC MAINS FAULT PS.PE.X
CONTROLLER UNREGULATED LOSS C.UL.X
Overload Faults
RF AMP POWER SUPPLY CURRENT FAULT PS.OC.X
RF AMP POWER SUPPLY VOLTAGE FAULT PS.VE.X
DRIVE HIGH FAULT DR.OD.X
DRIVE LOW FAULT DR.UD.X
Off Faults
EXTERNAL INTERLOCK I.EXT.X
DOOR INTERLOCK I.DOOR.X
ENCODER SUPPLY FAULT E.SF.X
ENCODER CABLE INTERLOCK E.CI.X
OVERTEMPERATURE FAULT OT.OFF.X
AIR FLOW FAULT AF.FLT.X
Table M-2. Fault Abbreviation Chart
888-2339-002 M-23
WARNING: Disconnect primary power prior to servicing.