Blank Micro Display

Symptom

With the circuit breaker energized and power available to the power supply, the micro display is blank and the cooling fans in the power supply do not energize.

Fault

The control power circuit in the power supply is defective.

Solution

• Check the fuse located on the control transformer mounted on the back panel of the power supply.
  1. If the fuse is good, proceed to Step C.
  2. If the fuse is open, replace the fuse. If the fuse opens again, proceed to Step E.
  3. With an AC voltmeter, check to ensure supply voltage is available to the control transformer (Item 21). If voltage is present proceed to Step D. If no voltage is present, recheck the supply voltage to the power supply.
  4. With an AC voltmeter, check the output of the control transformer. It should be 115 VAC. If not, replace the transformer.
  5. There is a short circuit in the control circuit. Verify the interconnection wiring is correct. Isolate the interlocks to help locate the fault

Symptom

With the circuit breaker energized and power available to the power supply, the micro display is blank and no LED's are lit, but the cooling fans in the power supply are energized.

Fault

The supply voltage to the micro display is defective.

Solution

1. Check to ensure the ribbon cable between the driver board and the microcontroller is fully plugged in.
   1. Verify the cable is not damaged.
   2. Ensure the red striped side of the ribbon cable is connected to Pin 1 on each end.
2. With a DC voltmeter check for 24 VDC across C8 on the microcontroller .
   1. If good, replace the microcontroller.
   2. If bad, proceed.With a DC voltmeter check for 24 VDC on the driver board.
3. Measure the voltage at D30 cathode with respect to E10.
   1. If good, replace the ribbon cable.
   2. If bad, proceed.
4. With an AC voltmeter check the 115 VAC supply to the driver board at E11 and E12.
   1. If good, replace the driver.
   2. If bad:
      1. Check the wiring.
      2. Contact Enercon's Service Department for assistance.

Symptom

With the circuit breaker energized and power available to the power supply, the micro display is blank, but all the LED's are lit.

Fault

EPROM is defective.

Solution

Contact Enercon's Service Department for assistance.