My tripp.Lite Smart Pro 2U, Modle 2200 does not turn on. When holding power on / off button, it beeps on and beeps off, but never actually turn on. Also, the menue on the LCD does not come up to see the problem. If holding Mode and Mute together, the factory setting menue comes up, but can not do any thing other than going out of it by pressing power button. What is the problem?

Computers & Internet - Smart