Computer goes dark while on UPS

[Jeremy]

I have a Back-UPS XS 1500M with a PC and monitors connected. UPS load is between 16% and 28%, 122 VAC line voltage and battery at 98%, 27.4 VDC.  A few minutes ago while working on the computer, there was a click and my monitors went dark. The PC appeared to go to sleep/hibernation, and came back to where it was at with all previous application open.  The power did not go out at the building.  I recall this happening once before, maybe 1 1/2 months ago.  I see that that next to the device status, it says "Online (Software Update Available).

Any suggestions on what happened?

Thanks

[Teken]

How old is the unit and has the battery ever been replaced?!? If not disconnect the power from the wall.

What happens?!?

If nothing happens besides going to battery backup. Take a power bar that has a switch for on / off.

Plug the power bar directly to the wall outlet. Plug the UPS to the power bar and wait for the system to show on line.

Now quickly toggle the power button on the power bar on-off-on several times.

What happens?!?

NOTE: If you remove AC Mains (Power) from the outlet as outlined in step one and the UPS shuts down the battery is toast - replace! This is why I asked how old the system / battery was.

If in step two the UPS continues to operate the power bar test is to identify other issues / problems. Keep in mind every UPS has a published transfer time based on Ms (millisecond). 

As such the UPS may not be transferring fast enough for the computer system. Thus rebooting due to a loss of input power.

Let me know the results of both tests and the battery installation date! 👍

[Jeremy]

The unit was purchased in July 2024. The battery was DOA with a bad terminal.  APC/Schneider sent a new battery and it has ban fine.  The unit appears to operate correctly when unplugged from the wall. Alarm beeps, display shows time remaining (about 40 minutes). Operates as is should with several rapid power losses.

When the "reboot" happened, it appeared to be more of a hibernation.  All windows and programs remained open as the were when it went dark.

Windows 10 Pro, current with updates.

Thanks

[Teken]

Are you sure the cables and ports to and from the monitor are fine?!?

This sounds more like a loose connection or failing monitor. It’s hard to validate this simply by your brief comments thus far and not seeing this first hand.

Regardless there’s no way for any computer no matter the state to instantaneously start back up with open files / applications.

All states regardless of sleep, hibernate, suspend require time to come back up.

You can see this every time because the process takes time.

Lastly, it’s not clear to me if you completed step two. By toggling power very quickly to see if the UPS is able to transfer over to battery without the computer rebooting. 

[Jeremy]

Sorry for being unclear regarding the "restarting" of the computer. It is not instant on. It comes back similar to hibernation or sleep, with the fan coming back up to speed etc, and programs that were open remain open.

I did try rapid on/off with power to the UPS, and it operated as it should.

This has only happened twice, which obviously makes it hard to troubleshoot. Do you know if there are any firmware updates, and if so, could that have caused it?

Thanks

[Teken]

The APC Back-UPS line does not have updatable firmware. I would review the APC Power Chute logs and those captured by the UPS LCD.

I would compare those logs to the two events you saw. Provide the same here for review including the data / event logs.

If there are no data logs simply screen capture the different tabs that show the following metrics: Input / Output voltage, frequency, battery voltage / capacity. 

Your specific model UPS has a published transfer time of 8-12 ms which is typically fast enough for most computer PSU’s.

The only way to validate that isn’t the root cause is to toggle the power bar switch extremely quickly. You’ll find that very hard to accomplish more than once unless the power is controlled by button vs a toggle switch!