Maintenance
1705A Spectrum Monitor
6- 13
Table 6- 2: Power Supply Fault Symptoms (Cont.)
Power Supply cycles OFF/ON
Output Check (Low Volts),
or High Voltage Oscillator Check (High Volts)
Does not power up
Control Circuit Check (Low Volts)
5 V not regulating
Error Amplifier Check (Low Volts)
Improper crt display
High Volts Supply
NOTE
. A 20
Ω
, 2 watt resistor should be used as a load for the Low Volts Supply.
Disconnect J4 and connect the 20
Ω
resistor between W1 (+5 V) and TP1
(secondary ground).
1.
Preliminary Checks
a.
A properly functioning and loaded Low Volts Supply will output the
voltages listed in Table 6--3. Use the DMM to measure the voltages
between TP1 and the voltage test points. If the supply is not regulating
properly, continue with the procedure.
Table 6- 3:
Low Volts Supply Voltages
Test Point
Voltage
W1 -- (+5 V)
+4.88 to +5.12 V
W4 -- (+15 V)
+14.0 to +16.0 V
W3 -- (--15 V)
--14.0 to --16.0 V
W2 -- (+40 V)
+39.0 to +41.0 V
NOTE
. The Low Volts Power Supply troubleshooting is performed without
applying ac power.
b.
Disconnect ac power from the instrument. Disconnect the instrument
from the Power Supply by removing the jumper from J4.
c.
Use the digital multimeter to measure the voltage between TP2 and the
tab (drain) of Q9. Be sure the voltage is near 0 V before proceeding.
Low Volts Supply
Содержание 1705A
Страница 13: ...Service Safety Summary xii 1705A Spectrum Monitor ...
Страница 17: ...Preface xvi 1705A Spectrum Monitor ...
Страница 18: ...Introduction ...
Страница 19: ......
Страница 38: ...Operating Instructions ...
Страница 39: ......
Страница 61: ......
Страница 62: ...Installation ...
Страница 63: ......
Страница 72: ...Theory of Operation ...
Страница 73: ......
Страница 93: ...Theory of Operation 4 20 1705A Spectrum Monitor ...
Страница 94: ...Checks and Adjustments ...
Страница 95: ......
Страница 123: ...Checks and Adjustments 5 28 1705A Spectrum Monitor ...
Страница 124: ...Maintenance ...
Страница 125: ...Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 FAX 781 665 0780 TestEquipmentDepot com ...
Страница 154: ...Options ...
Страница 155: ......
Страница 158: ...Replaceable Electrical Parts ...
Страница 159: ......
Страница 189: ...Replaceable Electrical Parts 8 30 1705A Spectrum Monitor ...
Страница 190: ...Diagrams Circuit Board Illustrations ...
Страница 191: ......
Страница 193: ......
Страница 213: ......
Страница 214: ...Replaceable Mechanical Parts ...
Страница 215: ......
Страница 223: ......