Too sensitive (possibly damaged UPS)?

[Anonymous user]

Hi,

I have a Back-UPS RS 800 and a few weeks ago it suddenly refused to go online after start-up and kept falling back to battery. Naturally the first thing I did was to replace the batteries since they were approximately 4 years old but now it exhibits the same thing again.

I can turn it on, the battery check starts running, the green light switches off, the orange one comes up and I can hear and see (for testing purposes I use a normal light bulb) how it switches to battery but it will never ever switch back. Everything is set to the lowest possible sensitivity. But when I connect it to my fully functional Back-UPS CS 650 the dang thing works without a glitch.

Any ideas? The only think that comes to my mind is that I remember setting the Hz settings back when I bought it. But that settings is gone from the software? Is that possible? Might that wrong setting cause that?