When the Backup is the Failure

At 21:30 last night I was watching the last episode of Law & Order: Criminal Intent Season 4. In the final minutes of the program, there as a high-pitched audible tone.  I thought the audio from the Netflix Online viewing had gone crazy.  But when the episode completed and I had closed my browser, the tone coninued.  Then my computer reported that there was a missing LAN connection, assuming that my LAN was unplugged.

So I'm thinking the scream is a failing hard drive and/or my main desktop computer is having a meltdown.  I run around to the back of my setup and check the cables connecting the machine.  The annoying shrill whistle is continuing though it varies a little and doesn't seem to be quite so loud.

I figure rebooting might help, and I start that.

As I lean back waiting for the reboot to take, I look over and notice that my stack of network devices is all dark.  The router, hub, Wireless Access Point, and Broadband modem are all dark.  Walking over for a closer look I see that my Windows Home Server is shut down and it is the battery-backup unit that I use for the WHS and network units is on "Overload" and that is the source of the high-pitched tone.

I recycle the BBU and the network appears to be coming back up, I restart the Windows Home Server also. 

Then it happens again.  I do some obvious things like test that plugs and connectors are seated, try the circuit breaker on the back of the BBU, but nothing works.  I can move some wires and route power around the BBU, leaving it sitting there unconnected but still howling at me.

The LAN comes up fine without the BBU.  I finally got the refuse-to-die alarm to quiet by holding down the front-panel button for an extended time, then releasing it.  It is sitting quietly dead, unconnected, at this point. 

I wonder whether the BBU had been on battery for some period of time and finally ran out of juice.  Also, there had been some intermittent power hiccups several hours earlier in the day.  I saw the desktop BBU click in and out, and the lights flickered in my office.  I didn't hear anything from the LAN BBU, although I clearly don't even think about that one.  It just sits quietly nearly out of sight, and I pay not attention to it.  Until now.

Meanwhile, I think I will get a replacement unit for this failing APC Back-UPS XS 900.  Another XS 1300 may simply work better, although I don't think I need that much capacity. Then I'll see if this one will recharge (or not). 

All through this, it never occured to me that smoke alarms are similar.  But none of mine sound like that, fortunately.