Symmetra LX, power failure fault

[BillP]

we are the authorised service provider for single phase ups APC product in Oman,

recently we went to start up Symmetra lx 8kva ups, but it was purchased 2 years back, now they are called to start up, from 2 years it was off condition. i turned on this ups, after 2 min it is going to battery mode, and i checked in faults and diagnostic showing no faults, and i checked through NMC and showing input power failure fault, even input is there with 235vac,i turned off and again turned on, ups is turned on after 2 min again going to battery mode and showing input failure fault in NMC home page, but in ups display still showing 235VAC input. after some time battery discharged fault is coming, and battery run time showing 0hr 7 min even after putting to charge more than 5 hr run time is same only not increasing.

please give me the solution, which one is problem