Power Supply - Fluke Autoranging CombiScope PM3370B Service Manual

PERFORMANCE TEST
6.3 TEST PROCEDURE
6.3.1 Preliminary settings
Test equipment:
None
Settings/procedure and requirements:
1 - If not present install 2 penlight (LR6) back up batteries in the holder at the rear panel of the
oscilloscope.
2 - Turn on the oscilloscope under test.
3 - Press the STATUS and TEXT OFF keys simultaneously. This assures that the oscilloscope
follows the default reaction when the green AUTOSET key is pressed. You can verify that the
oscilloscope is in analog mode by pressing the RUN/STOP key. If you are in analog mode, the
message 'PLEASE FIRST SWITCH TO DSO' is displayed. The now following steps are
applicable for PM3390B and PM3394B.
4 - Press the UTILITY menu key to display the UTILITY menu.
5 - Press softkey AUTOSET to display the UTILITY AUTOSET menu.
6 - Press the relevant softkey to put the oscilloscope in the 'userprog' mode; the text 'userprog'
must be intensified.
7 - Press softkey VERT.
8 - Select with softkey '1MΩ / 50Ω / unaffect' the 'unaffect' position.
9 - Check for the instrument settings in the lower part of the viewing area: when not available
press TEXT OFF until the maximum amount of information is displayed.
6.3.2

Power supply

This test checks the proper operation of the power supply at all possible line voltages.
Test equipment:
Variable voltage transformer (VARIAC)
Test set-up:
TO MAINS
Settings/procedure:
1 - Adjust the input line voltage to the oscilloscope (output from VARIAC) to a desired value
between 100 and 240V (rms), frequency 50...400 Hz.
2 - Press POWER ON on the oscilloscope.
3 - Apply the Probe Adjust signal from the front panel of the oscilloscope to input CH1, e.g., by
means of a 10:1 probe.
4 - Press the green AUTOSET key.
VARIAC
OUTPUT
OSC POWER CORD
OSCILLOSCOPE UNDER TEST
CH1 CH2
Probe
Adjust
PROBE
CH3 CH4
MAT4127
9303
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