GL-T8541 PA
Glenayre Document Number: 9110.01002
CHECKOUT AND MAINTENANCE
09/10/99
Page: 7-14
Copyright © 1997 Glenayre
Low or zero RF output, driver board or one PA
board with zero current
Open
amplifier-board-current-sensing
resistor on metering board
Replace metering board
Output power OK, low or zero VDT amplifier
currents
Bad metering board 36 V
regulator
Replace metering board
Transmitter faults, fault indications show AGC
reading of -15 Vdc, zero PA currents, zero RF
output power, driver current OK, temperature
reading too low,
Open metering board +7.5 volt
regulator
Replace metering board
Transmitter faults, fault indications show zero RF
output, zero amplifier currents
Open +5 volt metering board
regulator
Replace metering board
Transmitter functions normally except that some PA
board current always flows
Open -15 volt metering board
regulator
Replace metering board
PA cooling fans always run at full speed when
metering board jumper JP5 is in position A, even
when PA temperature is low
Open +12 volt metering board
regulator
Replace metering board
1. RF output normal, Driver current at idle value
when transmitter is unkeyed
2. Transmitter faults, fault indications show: RF
output zero, zero amplifier currents, low driver
current
Bad keying circuit on metering
board
Replace metering board
Transmitter faults off, fault indication shows low RF
output indication on VDT display with amplifier
currents near their normal value
Bad metering board forward
power amplifier (U5B)
Replace metering board
Improper VDT display parameters for power
amplifier.
Bad metering board multiplex
chips U15, U16, U17A, or
U17B
Replace metering board
Large error in VDT temperature indication
Bad temperature circuit
Replace metering board,
if error persists replace
combiner board.
Transmitter overheats, one or both cooling fans not
operating with metering board jumper JP5 in
positions A or B.
One or both cooling fans not
operating, or blown fan fuse
Replace fan fuse or
defective cooling fan(s)
Table 7-3 PA Module Faults
Symptom
Problem Area
Item to Replace
