Simpson 460 4 Series - Page 55

Sympton
2. LOW intensity on nu-
merical display in
battery operation,
(460-4D).
. No indication on the
numerical display
when Instrument is
AC line operated (no
cells installed).
. Batteries do not re-
spond to charge.
460-4D operation OK
when connected to
AC power.
. Operation normal on
all functions and
ranges except AC and
DC Current.
. Indications fluctuate
and/or drift, even
though indication is
OK and 000 with the
Servicing Instructions
Probable Causes
Cells not fully charged.
a. Low or no voltage
at power source re-
ceptacle.
b. Line cord discon-
nected.
c. Defective line cord.
d. Line fuse open.
Cells defective, not in-
stalled properly, mak-
ing poor contact, or
missing.
Current fuse F2 open.
Fluctuations and/or
drift are being gen-
erated by the device
being measured or the
Cure
Check battery voltage.
Refer to para. 4.3.2.
If battery checks low,
remove cover and
check that the cells
are installed correctly
and making good con-
tact. (Refer to 7.2.) If
they are, replace cover
and charge battery
overnight. Refer to
para. 7.3.
a. Restore correct
voltage at power
receptacle.
b. Connect line cord.
c. Repair or replace
cord.
d. Replace line fuse.
(Refer to para. 7.4.)
Remove cover and
check that cells are in-
stalled correctly and
making good contact.
Refer to para. 6.3. If
they are, check the
voltages of the indi-
vidual cells. Replace
those which check sig-
nificantly lower than
normal (1.25 volts).
Replace fuse to (para.
7.4).
Use proper shielding,
grounding techniques
and connections to
minimize “pick-up” of
7-5