Prokit's Industries MT-1233С - Manual (Page 13)

MAINTENANCE
Beyond replacing batteries and fuses, do not
attempt to repair or service your Meter unless you
are qualified to do so and have the relevant
calibration, performance test and service
instruments. The recommended calibration cycle is
12 months.
To clean the terminals
a) Push the Meter OFF and remove test leads.
b) Shake out any dirt that may be in the terminals.
c) Soak a new swab with isopropyl and work around
the inside of each input terminal
d) Use a new swab to apply a light coat of fine
machine oil to the inside of each terminal.
FUSES TEST
Warning
To avoid electric shock or injury, remove the test
leads and any input signals before replacing the
fuses
1. Turn the rotary switch to 200mA position.
2. Use a multimeter to measure resistance of
"VΩmA" terminal or 10A terminal to COM
terminal.
 A good mA terminal or 10A terminal fuse is
indicated by a reading between 0Ω and 10Ω.
13
 If the display is overloaded, replace the fuse and