43
Leica ST4020
• Check whether there is a general power failure (no power).
• Check whether the power plug is inserted correctly into the wall outlet and whether the wall
outlet is switched on.
• Check whether the power cable is plugged into the socket on the instrument properly.
• Check whether the power switch is switched on correctly.
• Some instrument malfunctions / failures are caused by defective fuses.
Check whether one or both secondary fuse(s) is/are faulty.
7.4 Power failure
7. Troubleshooting
Before replacing a fuse, always switch the instrument off and unplug from power
supply. Defective fuses may be replaced only with the replacement fuses supplied
together with the instrument.
Before plugging the power cable back
in and switching on the instrument,
you must have identified and correct-
ed the cause of the faulty fuse.
To replace a fuse, proceed as follows:
• Using a screwdriver (
30
), carefully remove
the fuse insert (
34)
on the rear side and flip
upward.
• Remove the fuse insert (
31
) - it contains two
fuses on the rear (
32
).
• Check that the thin wire (
33
) in the glass capil-
lary of a fuse is intact. If not, the fuse must be
replaced.
Fig. 33
• Insert the fuse insert with the two fuses and
start up the instrument again.
30
33
34
31
32
