APC BR1000-IN 4th replacement problem again

The fourth replacement i got for my 13 month old BR1000-IN said it has developed some internal fault look at the pic:



Whenever this pops up the UPS will go bad soon so i registered a complaint with the APC guys as soon as the 4th replacement popped this up which was just 14 hrs after the replacement.As i have feared, i was playing call of duty 4 today morning i heard this beeps so looked at the UPS three lights(OVERLOAD,REPLACE BATTERY,ON BATTERY) were blinking the green ON light was NOT blinking.So exited the game to find this NEW popup:



So i shut down the PC and ups restarted again now no popups whats happening here.

I did a self test it passed:

Whats your PSU? Have you tried using the UPS with someone else's PC? Could be the source of the problem, as it cant be a coincidence that you face the same problem with 4 Units. The only common factor is your PSU here.

Its corsair VX450.

And the power from the mains itself!

Get the UPS checked from your friend's place. Leave it for a couple of days' time. Discharge the UPS completely and charge it. See if it shows the same problem.

The APC eng. who came to my house checked all that said all wiring,earthings etc are OK on my side.But he said the earth and neutral are looped somewhere but it wont have any effect on the UPS thats what he said.