My ups does not light, which may be the cause?

There could be 2 reasons for this:

First is simple - the LED indicator failed and the unit is fine

Second is the battery is about dead or below the lower limit to hold a charge.

There should be 2 indicator lights on the unit. One for power status and one for check battery or if the unit is overloaded.

One simple test for the battery is to remove all connections to the unit - plug in a small lap of 75 watts and time how long it takes to discharge the battery. With just a lamp on a 750 watt system you should get at least 44 minutes of run time, since that is less than half of the load capacity.

If the unit is over three years old - chances are the battery has to be replaced. That is something you get from Tripp Lite or a qualified reseller.

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