Komatsu PC200 -8 Shop Manual page 31

00 Index and foreword
4. Handling controller
1) The controller contains a microcomputer
and electronic control circuits. These con-
trol all of the electronic circuits on the
machine, so be extremely careful when
handling the controller.
2) Do not place objects on top of the control-
ler.
3) Cover the control connectors with tape or
a vinyl bag. Never touch the connector
contacts with your hand.
4) During rainy weather, do not leave the
controller in a place where it is exposed to
rain.
5) Do not place the controller on oil, water, or
soil, or in any hot place, even for a short
time. (Place it on a suitable dry stand).
6) Precautions when carrying out arc welding
When carrying out arc welding on the
body, disconnect all wiring harness con-
nectors connected to the controller. Fit an
arc welding ground close to the welding
point.
5. Points to remember when troubleshooting
electric circuits
1) Always turn the power OFF before discon-
necting or connecting connectors.
2) Before carrying out troubleshooting, check
that all the related connectors are properly
inserted.
a Disconnect and connect the related
connectors several times to check.
3) Always connect any disconnected con-
nectors before going on to the next step.
a If the power is turned ON with the
connectors still disconnected, unnec-
essary abnormality displays will be
generated.
4) When carrying out troubleshooting of cir-
cuits (measuring the voltage, resistance,
continuity, or current), move the related
wiring and connectors several times and
check that there is no change in the read-
ing of the tester.
a If there is any change, there is proba-
bly defective contact in that circuit.
PC200, 220-8
SEN00094-05
17