Section 8 − Pre-Power Troubleshooting; Checking Unit Before Applying Power - Miller Millermatic 350P Technical Manual

SECTION 8 − PRE-POWER TROUBLESHOOTING

8-1. Checking Unit Before Applying Power

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Discharge input capacitors according to Section 8-2 and be sure voltage is near zero before touching any parts.
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Before troubleshooting or applying power to unit, complete following checks to avoid causing further damage.
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Although control board PC1 and hall device HD1 are briefly checked in this procedure, more complete tests may be needed later
for these parts. This check is simply to get a basic okay to power up unit.
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The pre-power checklist should be followed if any of the following conditions exist:
the unit is completely inoperative;
the symptoms are unknown;
visual damage is found on any of the following components: capacitors C3 and C4, control board PC1, IGBT power modules PM1 and PM2, inter-
connecting board PC2, or input rectifier SR1;
there is no output or limited output.
TM-1327 Page 42
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See Section 9-3 for test points and values and Section
12 for parts location.
Millermatic 350