6-39
7. Rotate the following infinite rotation pots:
Trigger Level Control
Holdoff Control
Figure 6-7. Mux Test waveforms.
4917-28
CH 2 POSITION
TRIGGER HOLOOFF
LEVEL CONTROL
CONTRO L
ov
5V
I
HORIZONTAL POSITION
CH
,...---- 5V MUXSEL2
R800
OV PIN
4
A 100",s
CH
1
CH 1 5V
CH 2 2V
AOUTO
R800
PIN 8
6. Check that the pots go into the rate region at both extremes of rotation and that the voltage level
for each pot moves smoothly from one amplitude level to the other (approximately 0.5 V to 5 V
total range) as the pot is rotated. See the test waveform illustration to identify the portion of the
waveform associated with the control being rotated.
5. Rotate the following rate position pots:
CH 1 Vertical Position
CH 2 Vertical Position
Horizontal Position
Cursor/Delay Position
4. Power on the 2430. When it does the power-on test, it will signal a test failure of 4300 on the
Trigger LEOS, and there will be no display on the 2430 crt.
3. Connect the test scope to observe the AOUTO signal at RSOOpin S. Trigger the test scope on
MUXSEL2 at RSOOpin 4. Set the SEC/DIV switch to 100 ~s and the VOLTS/DIV to 2 V.
2. Ground the MUXINH signal at the end of RS15 nearest the front of the 2430 to DGND.
1. Turn the power off and connect pins 2 and 3 of J155 together.
An intermittent failure or noisy front panel pot can produce inconsistent control changes. To test indi-
vidual pots for smooth operation and full range control limits, the Front Panel MUX SELECT test may
be used to provide stable triggering.
Front Panel MUXTEST:
Table
6-6
(cont)
Maintenance-2430 Service
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