Hitachi RAS-(3-6)HVRNM2E Service Manual page 327

8 Troubleshooting
Procedure:
Remove all the terminals of the transistor module before check. If items (a) to (d) are performing and the results are satis-
factory, the transistor module is normal. Measure it under 1kΩ range of a tester. Do NOT use a digital tester.
a. By touching the + side of the tester to the P terminal of tran-
sistor module and the - side of tester to U, V and W of transistor
module, measure the resistance. If all the resistances are from 1
to 5kΩ, it is normal.
b. By touching the - side of the tester to the P terminal of transis-
tor module and the + side of tester to U, V and W of transistor
module, measure the resistance. If all the resistances are greater
than 100kΩ, it is normal.
c. By touching the - side of the tester to the N terminal of transis-
tor module and the + side of tester to U, V and W of transistor
module, measure the resistance. If all the resistances are from 1
to 5kΩ, it is normal.
d. By touching the + side of the tester to the N terminal of tran-
sistor module and the - side of tester to U, V and W of transistor
module, measure the resistance. If all the resistances are greater
8
than 100kΩ, it is normal.
3. Checking method of diode module
Outer appearance and internal circuit of diode module
If items (a) to (d) are performing and the results are satisfactory, the diode module is normal.
Measure it under 1kΩ range of a tester. Do NOT use a digital tester.
a. By touching the + side of the tester to the + terminal of diode
module and the - side of tester to the ~ terminals (3 NOs.) of the
diode module, measure the resistance.
If all the resistances are from 5 to 50kΩ, it is normal.
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SMGB0064 rev.0 - 08/2011