A customer called a few weeks ago saying they did not have Internet access and could not access the network. A storm had gone through the area the night before, so I started by having them check to make sure the Internet equipment was online. There were no problems with the network equipment, so I asked the onsite IT person to check the server rack. Upon walking into the server room, I could hear alarms going off. He said it was the UPS that was beeping.
Their DHCP, DNS, WPAD, and File Server is all on one server, which is plugged into this UPS. I went onsite and bypassed the UPS for power to their servers. The UPS would not turn the outlets on and referred to an overload error. I called APC tech support and they said this error meant that there was an internal fault in the UPS and it would have to be replaced. A replacement UPS was sent and installed. It appears that an electrical event occurred during the storm the night before and messed up the UPS. Since then, the company has purchased an additional UPS so that one power supply from each server can be plugged into each UPS. Hopefully, if this ever occurs in the future, one of the UPSs will remain online.