back-ups es 750 speakers cycle on/off after sleep mode

[Anonymous user]

I recently purchased a Back-UPS ES 750 to use with my iMac (Intel) 24 in. aluminum. I followed the instructions to set threshold settings to 'high' because I thought my external speakers (Harman/Kardon SoundSticks II) needed such a setting to turn off when my iMac goes into sleep mode. I plugged my speakers into a 'controlled by master' outlet. When my iMac now goes into sleep mode, the speakers then cycle on/off for approximately a minute before going off. (blue light on woofer goes off/on and clicking sound is heard). This on/off with speakers is probably not doing them any good but I'm wondering if this is just the way things work since when my iMac goes to 'sleep', the power level is probably reducing gradually . - ?? Any comments ?

Thanks much,
pb in California

[Erasmus_apc · Accepted solution]

It does sound like the sleep "draw" of the iMac may be an issue. We have observed 21" and above iMacs drawing a surprisingly large amount of power in very quick bursts when in sleep mode, often times above the 60w threshold of the UPS' "high" setting. I am not sure why this happens, since otherwise the iMacs are +very+ efficient when in sleep mode. I would suggest investigating to see if there is anything additional you can configure on the Mac to have it power down as many components as it possibly can. Are you using the USB communication cable for use with Energy Saver/PowerChute that came with the UPS?