Service
AVTMTTR330 Rev 3 March 2010
37
Troubleshooting
The Troubleshooting Guide, Table 6-1, is arranged to help you evaluate the
reasons for TTR test set malfunction. The table lists possible test set
malfunctions which may be encountered during operation and lists possible
causes. Electronic circuit repairs should not be attempted in the field. Refer to
Repairs
heading below. Refer to Section 7 for a list of spare parts.
Table 6-1. Troubleshooting Guide
MALFUNCTION POSSIBLE
CAUSE
Display stays blank after POWER switch is
turned on.
No service power
Defective line cord
Defective fuse(s)
Defective display or electronics
Error message:
ANALOG OFFSET VOLTAGE
HIGH
and/or
ANALOG GAIN OUT OF
TOLERANCE appears after self-test is
complete.
Out of tolerance condition(s) in
measurement circuit
Red TEST VOLTAGE ON lamp does not
light on start of testing.
Defective lamp
EMERGENCY TEST OFF switch
is not released
Problem in measuring circuit
One of the following messages appear on the
test result screen.
CHECK CONNECTIONS
PHASE A (or B, or C) EXCITATION
CURRENT TOO HIGH;
TURNS RATIO TOO LOW, <0.8; or
PHASE A (or B, or C) TURNS RATIO
TOO HIGH;
CHECK PHASE A (or B, or C)
CONNECTIONS, REVERSED;
CHECK PHASE A (or B, or C)
POLARITY
Abnormal operating condition
Incorrect setting of
TRANSFORMER TYPE in the
quick test setup or the full test setup
1 menus
Incorrect connection of leads
Defective test leads
Incorrect marking of a transformer
Problem in test specimen
Problem in measuring circuit.
RATIO and/or Iexc (mA) readings erratic.
Defective test leads (open circuit,
poor connection)
Severe abnormal transient in service
power
Problem in test specimen (poor
connection)
Problem in measuring circuit
