APC Back-UPS BX1600MI-GR dead

[zlatiborac_apc]

Device is 6 months old and has been purchased new.

Only 2 devices connected to UPS are a touchscreen register (which I triple checked for consumption and is around 80W per its manual), and a small printer used for printing receipts).

APC worked fine for this 6 months but yesterday during the working hours it started beeping (employee who turned it off doesn't remember were the LED flashing or not, the only thing he remembers is that beeping lasted for some hours, and when he disconnected UPS it was hot).

I thought that the battery was empty, and today when I tried to turn it on, it won't power on. Small fan on the back of device is spinning, and the whole device is cold.

Any advice on what to try more before I send it back to the shop, or throw it through the window since this is the second APC that died on me in last 2 years. This one in work and another at home.