Suggestion for repairing UPS?

[Impmon]

I have an UPS that has a good battery but refuses to work at all. It
is BC PERS200 (200VA or 125W) and I often use it with my laptop during
power failure to stay in touch.

Anyway it just up and died one day. I checked, the battery is still
charged at just a bit above 12v (how do I check its capacity? It
should be about 4.5A fully charged) but if I turn on, no "Backup ON"
light comes up and there's no power output. There's also no light on
"Line Good" when plugged in as well and might as well be plugged into
a nonworking AC outlet.

I took it apart and checked 2 onboard fuses (40A and 5A) and both are
good, there's no obvious sign like burned resistor, bulging caps, or
burn mark on the PCB. I could replace that UPS but I wanted to see if
I can fix it for under $10 first since shipping's so expensve on these
bricks and most local stores like Best Buy or Circuit City carries UPS
that are way too much for my need (not to mention they put a hefty
markup for profit) 600VA? I have never had power failure lasting more
than 3 days and 200VA is enough.

 

[Jerry G.]

Before you cause any damage, don't mess with the UPS electronics. The
battery has to be tested under load to determine if it is really good or
not. If the UPS sees the battery not being up to specs, it will not
start-up. You must try a new battery to properly test the unit.

--

Jerry G.
=====


I have an UPS that has a good battery but refuses to work at all. It
is BC PERS200 (200VA or 125W) and I often use it with my laptop during
power failure to stay in touch.

Anyway it just up and died one day. I checked, the battery is still
charged at just a bit above 12v (how do I check its capacity? It
should be about 4.5A fully charged) but if I turn on, no "Backup ON"
light comes up and there's no power output. There's also no light on
"Line Good" when plugged in as well and might as well be plugged into
a nonworking AC outlet.

I took it apart and checked 2 onboard fuses (40A and 5A) and both are
good, there's no obvious sign like burned resistor, bulging caps, or
burn mark on the PCB. I could replace that UPS but I wanted to see if
I can fix it for under $10 first since shipping's so expensve on these
bricks and most local stores like Best Buy or Circuit City carries UPS
that are way too much for my need (not to mention they put a hefty
markup for profit) 600VA? I have never had power failure lasting more
than 3 days and 200VA is enough.

 

[Impmon]

Before you cause any damage, don't mess with the UPS electronics. The
battery has to be tested under load to determine if it is really good or
not. If the UPS sees the battery not being up to specs, it will not
start-up. You must try a new battery to properly test the unit.

And how could I do that? I really don't want to spend $40 or $50 oin
a new battery only to find the USP still won't work.

Thanks.

 

[James Sweet]

And how could I do that? I really don't want to spend $40 or $50 oin
a new battery only to find the USP still won't work.

An automotive headlamp bulb is a good test load for a battery, if it's a 12v
battery the lamp should light at full brightness and not dim noticeably over
a few minutes of operation.