Thermal Arc 300GTSW Pro-Wave, Service Manual

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pro-wave 300gtsw
A-16
June 21, 2012
APPENDIX 9: DIODE TESTING BASICS
Testing of diode modules requires a digital Volt/Ohmmeter that has a diode test scale.
1. Locate the diode module to be tested.
2. Remove cables from mounting studs on diodes to isolate them within the module.
3. Set the digital volt/ohm meter to the diode test scale.
4. Using figure A-6 and A-7, check each diode in the module. Each diode must be checked in both the forward
bias (positive to negative) and reverse bias (negative to positive) direction.
5. To check the diode in the forward bias direction, connect the volt/ ohm meter positive lead to the anode (positive,
+) of the diode and the negative lead to the cathode (negative, -) of the diode (refer to figure A-6). A properly
functioning diode will conduct in the forward bias direction, and will indicate between 0.3 and 0.9 volts.
6. To check the diode in the reverse bias direction, reverse the meter leads (refer to figure A-6). A properly func-
tioning diode will block current flow in the reverse bias direction, and depending on the meter function, will
indicate an open or “OL”.
7. If any diode in the module tests as faulty, replace the diode module.
8. Reconnect all cables to the proper terminals.
Art # A-06015
VR COM
A
Forward Bias
Diode Conducting
Anode Cathode
Forward Bias Diode Test