Master TOC
TROUBLESHOOTING & REPAIR
FOR REPLACEMENT OF SWITCH ASSEMBLY
FILTER CAPACITOR POLARITY TEST
1.Perform this procedure with the input power removed. Perform the CAPACITOR DIS- CHARGE Procedure to remove any charge from the input filter capacitors.
2.Configure the machine for 230VAC opera- tion.
3.Attach the ohmmeter (set to 1 K ohm range)
across one of the 7.5K ohm bleeder resistors (R9 or R10). See wiring diagram.
4.Attach the positive meter probe to wire #9 and the negative meter probe to lead #12. The resistance should slowly increase to a value between 3K ohms and 3.5K ohms.
5.Repeat the procedure for the other bleeder (7.5K ohm) resistor.
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| FIGURE F.76 - AC SUPPLY LEADS | |||||
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| FUSE |
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ISOLATED | PRIMARY |
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| 5A |
| INPUT RECTIFIER: AC1 (T1) |
VOLTAGE |
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115 VAC |
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VARIABLE |
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| INPUT RECTIFIER: AC3 (T3) | |
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| 0 |
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| 115 VAC |
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SETUP THE POWER WAVE FOR PRETEST
1.Turn the input power switch to the OFF position.
2.Unplug P73. See wiring diagram.
3.Install the
4.Construct an isolated variable AC supply circuit as shown in Figure F.76 using the following equipment:
Isolation transformer 115vac @ 3 amps.
5 amp Variac.
5 amp Fuse.
5.Connect the variable AC supply leads to the Power Wave input rectifier terminals AC1 (T1), and AC3 (T3). See Figure F.76. Make certain the variac is at zero volts output.
WARNING
ALL AC SUPPLIES MUST BE ELECTRICALLY ISOLATED (Isolation transformers). THE PRINTED CIRCUIT BOARDS WILL BE DAM- AGED IF THE AC SUPPLIES ARE NOT ISOLATED.
6.Monitor the filter capacitor voltage as per Figure F.77.
WARNING
WARNING: ALL METERS AND OSCILLO- SCOPES MUST BE ELECTRICALLY ISOLAT- ED (Isolation transformers).
