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

4.5.

No LEDs and No Output

Check Items
Power Devices defective, AC or DC fuse is burn
The working voltage of the control board is out
of order.
CPU is down.
FIG. 4.5
Trouble-shooting
Please see table 4.3 and 4.4 .
1. Please check the circuit shown in fig.4-2.
2. Cut off the Utility. Remove the control board.
Supply a 36Vdc to CN5 and CN4 by a DC
Power supply, connect CN2 to the main switch.
Push on the main switch and to see if DC POWER,
i.e. VDD(17.5V), VCC(12V) and +/-5V is normal.
3. Check if Q1, Q6, Q7, Q25, D11, D12 and U4
Is normal.
4. Check if any abnormal output signal of the U9.
If the DC POWER is normal, the CPU could be
Down. Remove the battery harness from the
UPS and re-connect it back to its position.
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