SMX1500RM2U - Power Overload warning - with nothing plugged in

[Anonymous user]

We plug in an SMX1500RM2U unit that has been in storage for a few months... it completes the self test normally.. imput/output voltage shows 115V 60hz battery 100% - there is nothing plugged into the unit 0 Load.. after about 30mins the red light on the front (triangle with ! inside) and the unit will beep once every 60 seconds with the words "Warning Power overload" 

it is an older version of this model  (probably 5yrs old don't have firmware/ser# in front of me right now) but I remember the UPS Couldn't be firmware updated via the AP9630 only by a serial port which we didn't have any PC's with this connection..  has anyone seen this problem before?

[BillP · Accepted solution]

Your ups are over heat, and maybe the big chock inside ups are shorted and after a while this error happen.