Maintenance Warning - Matco Tools MD251 User Manual

9
Set Beeper Off
Press the RANGE button while turning the meter on to temporarily disable the Beeper feature.
Turn the rotary switch OFF and then back on to resume.
Beep-Jack™ Input Warning
The meter beeps as well as displays "InEr" to warn the user against possible damage to the meter
due to improper connections to the A, mA, or A input jacks when other function (like voltage
function) is selected.
Auto-Power-Off (APO)
The Auto-Power-Off (APO) mode turns the meter off automatically to extend battery life after
approximately 34 minutes of no rotary switch or push button operations. To wake up the meter
from APO, press the SELECT, CREST or REC button momentarily or turn the rotary switch OFF
and then back on. Always turn the rotary switch to the OFF position when the meter is not in use
Disabling Auto-Power-Off
Press the SELECT button while turning the meter on to temporarily disable the Auto-Power-Off
(APO) feature. Turn the rotary switch OFF and then back on to resume.
5) MAINTENANCE
WARNING
To avoid electrical shock, disconnect the meter from any circuit, remove the test leads from the
input jacks and turn OFF the meter before opening the case. Do not operate with open case. Install
only the same type of fuse or equivalent
Cleaning and Storage
Periodically wipe the case with a damp cloth and mild detergent; do not use abrasives or solvents.
If the meter is not to be used for periods of longer than 60 days, remove the battery and store it
separately
Trouble Shooting
If the instrument fails to operate, check battery, fuses, leads, etc., and replace as necessary.
Double check operating procedure as described in this user's manual
If the instrument voltage-resistance input terminal has subjected to high voltage transient (caused
by lightning or switching surge to the system) by accident or abnormal conditions of operation, the
series fusible resistors will be blown off (become high impedance) like fuses to protect the user and
the instrument. Most measuring functions through this terminal will then be open circuit. The series
fusible resistors and the spark gaps should then be replaced by qualified technician.