Started system back up and there was a big spark and burned electrical smell

Both units started emitting a loud beeping noise and had a strong acrid smell from the transformer area.

The unit has a bad smell like the ghost has been set free

It stopped working and will not work, even has a burnt plastic smell

The first time there was a power failure the following happened: 1) the computer stopped, as if it had been plugged into the wall, 2) the UPS began a continuous beep and gave off a nice burned electrical smell.

Finally I heard a sizzling noise and burning battery smell.

Unit had burning smell

No fire/smoke or acrid smell during or after failures

This does not work and has a bad burnt smell.

Both units started emitting a loud beeping noise and had a strong acrid smell from the transformer area.