789 
Users Manual
 
34 
Replacing a Fuse 
! Warning 
To avoid personal injury or damage to the 
meter, use only the specified replacement 
fuse, 440 mA 1000 V fast-blow, Fluke PN 
943121. 
Both current input jacks are fused with separate  
440 mA fuses. To determine if a fuse is blown: 
1.  Turn the rotary function switch to 
W.  
2.  Plug the black test lead into COM, and the red test 
lead into the A c input. 
3.  Using an ohmmeter, check the resistance between 
the meter test leads. If the resistance is about 1 Ω, 
the fuse is good. An open reading means that fuse 
F1 is blown. 
4.  Move red test lead to ^. 
5.  Using an ohmmeter, check the resistance between 
the meter test leads. If the resistance is about 14 Ω, 
the fuse is good. An open means that fuse F2 is 
blown. 
If a fuse is blown, replace it as follows. Refer to Figure 11 
as necessary: 
1.  Remove the test leads from the meter and turn the 
meter OFF. 
2.  With a standard blade hand screwdriver, turn each 
battery door screw counterclockwise so that the slot 
is parallel with the screw picture molded into the case. 
3.  Remove either fuse by gently prying one end loose, 
then sliding the fuse out of its bracket. 
4.  Replace the blown fuse(s). 
5.  Replace the battery access door. Secure the door by 
turning the screws one-quarter turn clockwise. 
If the Meter does not Work 
•  Examine the case for physical damage. If there is 
damage, make no further attempt to use the meter, 
and contact a Fluke Service Center. 
•  Check the battery, fuses, and test leads. 
•  Review this manual to make sure you are using the 
correct jacks and rotary function switch position.