[TriLUG] OT: Diagnosting APC Back-UPS Misbehavior

[Scott Chilcote]

Hi Folks,

Sorry to wander OT, but I've seen good advice on this list related
to UPS problems and I'm hoping someone has some insight.

I have two APC Back-UPS XS 800 units that I took offline last year when
they showed the "Replace Battery" light.  I ordered new batteries last
week, and put them in one of the units.  It did not come back to life as
expected.  It showed the "On Battery" light instead, and started beeping
four times.  This is what they do when the power goes off.

I tried resetting the unit (disconnecting the battery and the AC plug,
holding down the "On" switch for 60 seconds).  No change. 

Then I tried setting the unit's sensitivity to the lowest setting.  This
caused it to power up normally (green light).  However, it soon started
making a relay chattering sound, which is quite loud.  I shut it off.

Since I had another Back-UPS XS 800 that needed batteries, I moved the
batteries over to that unit.  I even changed out the cable and spacer
for the battery pair.  When I plugged it in - lo and behold - I had the
identical misbehavior.  Same "On Battery" state.  Same relay chatter
with the sensitivity set to low.

Next step: Read the manual.  It says to check the AC voltage level in
the house.  I tried the UPS on several different outlets around the
house, same problem.  I measured the AC voltage, and got 113VAC on my
meter.  We have four other UPSes of varying kinds, and they are working 
fine at the default sensitivity level.  The manual also says to
check the circuit breaker on the back of the unit.  I did that
earlier and found that neither one had tripped.

I checked the voltage on both of the new batteries (disconnected).  They 
make the meter swing to at least 12 VDC.

These UPSes were both made in late 2004 according to their serial
numbers.  Did they die at the same time, while unplugged?  Do they count
the number of battery replacements and self destruct (humor)? 

I spent some time looking at APC's forums, this does not appear to be a
frequent problem.  I tried their online support chat, but the trees
outside my window were visibly growing while I waited (both of their
level ones may be off this week).

Thanks for any cluefulness!

    Scott C.

-- 
Scott Chilcote
Cary, NC USA
scottchilcote at att.net