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I've got a Windows 7 desktop system with an APC UPS to provide backup power during power outages. I've got the UPS connected to the system with a USB cable so that the built-in Windows power utility can monitor the power level, and it's set up to hibernate the system when the battery level gets too low during an extended outage. The system powers down just fine, but when the power is restored to the UPS, the system stays off. How can I get it to turn back on?
Please note that I've already set the Power Management features of the BIOS to "Always On." I imagine the reason it doesn't power back on is because it had a clean shutdown.
For the record, I've tried the APC PowerChute Personal Edition software, which does make it automatically power back on, but it's got a pretty serious bug that keeps it from shutting down the system if someone is logged in remotely.
If at all possible, I'd like to do this without any additional software, but that's probably a long-shot.
[UPDATE] It appears that the way the APC software gets the system to turn back on is by having the UPS turn off the power to the outlets after the system shuts down, and then turning it back on when main power is restored. It does this by sending the UPS a message to turn off the power to the outlets 2 minutes after it starts shutting down the system - long enough to power down most systems. It seems that neither the built-in Windows Power Management or the apcupsd software I tested can perform this function, at least on the test system I've been using.
Many APC SmartUPS models with a network card will do this. It sends a Wake on LAN packet to the device. I do not believe BackUPS Pro models support a NIC. And the NICs are expensive. – Dave M – 2014-11-28T13:34:03.767
If it's set to "always on", it should restore power when AC power is restored. If not, the issue is still with the BIOS. – David Schwartz – 2013-08-29T19:53:08.187
@DavidSchwartz - Thanks, but from the computer's perspective, it's never actually lost power, because the UPS is providing backup power. Windows shuts itself down, but doesn't set whatever switch the APC software does that allows the UPS to tell the computer that the main power is back up. It's exactly like if you unplug a laptop - it hibernates at a certain battery level, but doesn't automatically power on once you plug it into an outlet again. – kevinmicke – 2013-08-29T20:04:37.330
Oh, so you need the UPS to cycle power so the computer will come back on. Or you need wake on USB. – David Schwartz – 2013-08-29T20:31:22.380
That could work - any idea how I can make it do that? It's an APC Back-UPS Pro 1000 (BR1000G). – kevinmicke – 2013-08-29T20:33:20.213