Tektronix 5110, Instruction Manual

Page: 52 / 128

Malntenance-5110
Multimeter
Description: Voltmeter, 10 megohm input impedance
and 0 to 250 volts range; accuracy, within 0.1%.
Ohmmeter, 0 to 20 megohms; accuracy, within 3%. Test
probes must be insulated to prevent accidental shorting.
Purpose: To check voltages and for general
troubleshooting in this instrument.
Recommended Type; TEKTRONIX DM 501 Digital
Multimeter (requires a TM 500-series power module).
Test Oscilloscope
Description: Frequency response, de to 2 megahertz
minimum; deflection factor, 1 millivolt to 5 volts/division. A
10X, 10 megohm voltage probe should be used to reduce
circuit loading.
Purpose: To check operating waveforms and for
general troubleshooting.
Recommended Type: TEKTRONIX 5110, 5A13N,
5B10N oscilloscope system or equivalent. Use a
TEKTRONIX P6108 or P6062A Probe.
3. Visual Check. Visually check the portion of the
instrument in which the trouble is located. Many troubles
can be located by visible indications such as unsoldered
connections, broken wires, damaged circuit boards,
damaged components, etc.
4. Isolate Trouble to a Circuit. To isolate trouble to a
circuit, note the trouble symptom. The symptom often
identifies the circuit in which the trouble is located. When
trouble symptoms appear in more than one circuit, check
the affected circuits by taking voltage and waveform
readings. Incorrect operation of all circuits often indicates
trouble in the power supply. Check first for correct
voltages of the individual supplies. See Table 4-3.
However, a defective component elsewhere in the instru­
ment can appear as a power-supply trouble and may also
affect the operation of other circuits.
Table 4-3
POWER SUPPLY OUTPUT VOLTAGES
Power
Supply
Output Voltage Range
Typical
120 Hz
Ripple
+200 V +175 V to +247.5 V 3 V or less
+30 V +29.82 V
to+30.18 V
3 mV or less
+5 V
+4.89 V to +5.11 V 2 mV or less
-30 V -29.89 V to -30.11 V 2 mV or less
TROUBLESHOOTING TECHNIQUES
The following troubleshooting procedure is arranged
to check the simple trouble possibilities before
proceeding with extensive troubleshooting. The first few
checks ensure proper connection, operation, and adjust­
ment. If the trouble is not located by these checks, the
remaining steps aid in locating the defective component.
When the defective component is located, it should be
replaced using the replacement procedure given under
Corrective Maintenance.
5. Check Voltages and Waveforms. Often the defective
component can be located by checking for the correct
voltages and waveforms in the circuit.
6. Check Instrument Adjustment. Check the adjust­
ment
of this instrument, or the affected circuit if the
trouble appears in one circuit. The apparent trouble may
be the result of misadjustment. Complete adjustment
instructions are given in Section 3.
Troubleshooting Procedure
1. Check Control Settings: Incorrect control settings
can indicate a trouble that does not exist. If there is any
question about the correct function or operation of any
control, see Fig. 1-2 in the Operating Instructions section.
2. Check Associated Equipment, Before trouble­
shooting, check that the equipment used with
this instru­
ment is properly connected and that the interconnecting
cables
are not defective. Also, check the power source.
7. Check Individual Components. The following
procedures describe methods for checking individual
components. Two-lead components that are soldered In
place are best checked by first disconnecting one end.
This isolates the measurement from the effects of surroun­
ding circuitry.
To avoid component damage, disconnect the power
source before removing or replacing semiconduc­
tors.
4-10
REV A, NOV 1978