No Led And No Output - Ablerex 3 MS series User Manual

6.5 No LEDs and No Output
3.Check if the U7 SG3525 is out of order.
4.Check if the Booster Transformer T2¡BT3 is open.
5.After replace the defective devices. To make sure the other parts of the
UPS is OK. Disconnect the logic board from driver board.
Cut off the Utility. Provide 96Vdc to CN5(+) and CN6(-) by a DC
Power Supply, connect CN4 to the main switch. Push on the main
switch and to see if DC POWER of UPS, i.e. VDD(18-16V),
VCC(12V) and +/-5V is normal.
FIG. 6.5
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