Hitachi YUTAKI Series - Page 223

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Checking procedure for main parts
SMGB0066 rev.0 - 12/2009
Troubleshooting
Service Manual
7
Checking the transistor module:
By touching the + side of the tester to the P 1.
terminalofISPMandthe-sideofthetestertoU,
VandWofISPM,measuretheresistance.Ifall
theresistancesaremorethan1kΩ,itisnormal.
By touching the - side of the tester to the P 2.
terminal of ISPM and the + side of the tester to
U,VandWofISPM,measuretheresistance.
Ifalltheresistancesaremorethan100kΩ,itis
normal.
By touching the - side of the tester to the N 3.
terminal of ISPM and the + side of the tester to
U,VandWofISPM,measuretheresistance.
Ifalltheresistancesaremorethan100kΩ,itis
normal.
By touching the + side of the tester to the N 4.
terminalofISPMandthe-sideofthetestertoU,
VandWofISPM,measuretheresistance.Ifall
theresistancesaremorethan1kΩ,itisnormal.
● Procedureusingadigitaltester:

note
The digital tester must be able to check semiconductors and continuity. -
BasedonthefolowingschemeofISPMwiththecontactor,thereactor,capacitorsandtheresistance,followthenext
procedures.
 
1. Byplacingajumperfrom+P1to-RSTor-Nto+RST,nocontinuityandnovariationonvoltagedropshouldappear.
2. ByplacingajumperfromP1to+RSTor+NtoRST:continuityandvariationonvoltagedrop(nearly0,365)shouldbe
displayed,andthesamevalueinallcases.Notthesamevaluemeansthatthediodemoduleisdamaged.