this literally caught out 3 IT guys. the manual says press 1-3 seconds to turn on which is generally standard on APC but if you do this it wont actually turn on, even tho the OSD is showing info its basically press for a good 1 second only its also hard to tell if its off or on because the OSD stays on in both scenarios, the UPS symbol on the front has a sizzag accross the battery, according to the manual this is faulty or end of life, this is also not correct. it will show this anyway. hope this helps someone,.