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Section 6.5: Special Testing
CAUTION
These tests require that the power supply is powered off. Turn the
front panel EPO to OFF. Turn the rear panel main switch to OFF.
Table 6.5: Diagnostics and testing procedures
PROBLEM
DESCRIPTION
POSSIBLE PROBLEMS AND SOLUTIONS
Cathode filament
current is zero or
lower than normal.
1. Faulty connection – Check cable and feedthru connections. Note:
With the source off, disconnect the source cable from the power supply.
Use an ohm meter and measure the resistance between pins A/D and
G/E. The reading should be 2 ohms or less to indicate the filament is
intact and properly connected.
Beam current zero.
1. Faulty connection – Check cable and feedthru connections. Note:
With the source off and at atmosphere, disconnect the source cable from
the power supply. Use an ohm meter and measure the resistance between
pin C and the anode. The reading should be 2 ohms or less to indicate
the anode is properly connected.
Accel current zero.
1. Faulty connection – Check cable and feedthru connections. Note:
With the source off and at atmosphere, disconnect the source cable from
the power supply. Use an ohm meter and measure the resistance between
pin F and the accelerator grid. The reading should be 2 ohms or less to
indicate the accel grid is properly connected.
Beam current and
Accel current higher
than normal
1. Check for accel to screen grid shorting. Note: With the source off and
at atmosphere, disconnect the source cable from the power supply. Use
an ohm meter and measure the resistance between pin B and pin F. The
reading should be open to indicate the body (screen grid) is not shorted to
the accel grid.
Neutralizer filament
current is zero or
lower than normal
1. Faulty connection – Check cable and feedthru connections. Note:
With the source off, disconnect the neutralizer cable from the power
supply. Use an ohm meter and measure the resistance between pins A/B
and C/D. The reading should be 2 ohms or less to indicate the filament
is intact and properly connected. Also check between either A/B or C/D
to ground. The reading should be open to indicate the neutralizer
filament is not in contact with ground. Also check between either A/B or
C/D to source cable pin F. The reading should be open to indicate the
neutralizer filament is not in contact with the accelerator grid.