5
Baker Instrument Company
The Measure of Quality
measuring if the supply that is defective is restored. If not, replacement of the Power
Supply board would be required. If a board is found to be loading a supply then any
component on that board that is tied to the supply can be suspect. To narrow to the
component level will require a one component at a time isolation from the supply via
desoldering.
1.
Loss of or loading of the –12 volt supply will cause no output in the surge mode when
the PTT button is depressed. The trace will be visible at its most right upper position
on the CRT and will be non-adjustable with the vertical or horizontal position
potentiometers.
•
Surge trigger will be present, but no surge waveform will be attainable when the
PTT is engaged.
•
In the Hipot mode, a Hipot trip LED will illuminate and the voltage bar will show
a six (6) division up and the current bar will be extended off the screen. No Hipot
output will be attainable and numeric display for voltage and current will stay at
zero (0).
2.
Loss of or loading of the +12 volt supply will cause a total non-operation of the tester.
There will be no display upon power up or self-tests or no change when any of the
output controls are used.
3.
Loss of or loading of +5 volt supply will cause a total non-operation of the tester.
There will be no display upon power up or self-tests or no change when any of the
output controls are used.
4.
Loss of crystal frequency X1 on the A/D board will cause the loss of positional trace
control with the surge waveform in the upper right quadrant.
•
In the Hipot mode, after PTT is depressed hipot voltage and current bars will
be the same as in step #1 but numeric display for voltage will show 11950
volts and the current will show 996.0
µ
A. Replace X1.
5.
Loss of crystal frequency on U6 on the A/D board will show an erratic unstable
sawtoothed pattern once the PTT button is depressed and also will fail the A/D
memory self-test upon power up. Replace U6.
6.
Loss of crystal frequency on XTA1 on the Controller board will cause total non-
operation of the tester. There will be no display upon power up or self-test, or no
change when any of the tester controls are used. Replace XTA1.
7.
Loss of frequency on Y1 on the Controller board will cause a blinking effect on the
tester CRT with no recognizable lettering or numeric display. Tester will not initiate
it’s self-tests nor will any controls have any change on the display. Replace Y1.
