OSMAC RDR: Testing Power Transformer Voltages
LESSON SUMMARY: This lesson is designed to assist the user in testing for the proper voltages for an OSMAC® RDR Power Transformer.
Special Tools Needed: Digital Multimeter
⚠ CAUTION: THIS LESSON MAY INCLUDE INSTRUCTIONS TO TEST HAZARDOUS VOLTAGES (120V-240V) THAT CAN CAUSE SERIOUS INJURY OR DEATH. IT IS RECOMMENDED THAT A LICENSED ELECTRICIAN BE CONTRACTED TO PERFORM SUCH TESTS.
🛑 STOP: ALWAYS TURN OFF THE POWER TO THE SATELLITE BEFORE REMOVING OR INSTALLING ELECTRONIC COMPONENTS.
To test the functionality of the Power Transformer for OSMAC RDR®, the voltages will need to be measured both loaded and unloaded. For detailed instructions on measuring the voltages of the Power Transformer for OSMAC RDR®, follow the guided steps below.
Measuring Power Transformer Voltages (Unloaded):
To measure the the Power Transformer Voltages unloaded, proceed with the following steps:
Start by powering off the satellite.
Disconnect the black, orange and red Power Transformer wires from the Receiver/Decoder Module. The black, orange and red wires supply power from the Power Transformer to the Receiver/Decoder Module.
Power the satellite back on.
Using a digital multimeter or voltmeter set to the AC Voltage setting, place one probe of the multimeter in the connector containing the black wire (Common) and one probe in the connector containing the orange wire (12VAC).
The multimeter should display a reading of 12.5-14.5VAC.
Next, using a digital multimeter or voltmeter set to the AC Voltage setting, proceed to place one probe of the multimeter in the connector containing the black wire (Common) and one probe in the connector containing the red wire (24VAC).
The multimeter should display a reading of 27-31VAC.
If the voltages displayed on the multimeter fall within the ranges outlined above, proceed with the loaded transformer test.
Measuring Power Transformer Voltages (Loaded):
Start by powering off the satellite.
Next, reconnect the black, orange and red wires to the appropriate tab connectors on the Receiver/Decoder Module.
*Note: When reconnecting the black, orange and red wires to the Receiver/Decoder Module, leave the connectors containing the wires slightly unseated to allow access for the multimeter probes.
Power the satellite back on.
Using a digital multimeter or voltmeter set to the AC Voltage setting, proceed to place one probe of the multimeter on the metal connector on the Receiver/Decoder Module containing the black wire (Common) and one probe on the metal connector on the Receiver/Decoder Module containing the orange wire (12VAC).
The multimeter should display a reading of 11.5-13.5VAC.
Next, using a digital multimeter or voltmeter set to the AC Voltage setting, proceed to place one probe of the multimeter on the metal connector on the Receiver/Decoder Module containing the black wire (Common) and one probe on the metal connector on the Receiver/Decoder Module containing the red wire (24VAC).
The multimeter should display a reading of 26-29VAC.
If the voltages displayed on the multimeter do not fall within the ranges outlined above, the utility voltage (120VAC or 240VAC) will need to be tested.
The lesson for testing for 120VAC or 240VAC utility voltage can be found here.
If the utility voltage has been tested and the voltage measured falls within the acceptable range, but the voltage readings for the Power Transformer do not fall within their acceptable ranges, the Power Transformer is damaged and should be replaced.
Replacement Power Transformers can be purchased here.
Lesson tags: toro, osmac rdr, toro osmac rdr, osmac rdr repair, osmac rdr help, osmac rdr troubleshooting, osmac rdr exchange, osmac rdr motherboard, osmac rdr transformer, power transformer, voltage test, boardtronics
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