APC ES 550 clicking noise - time to replace the unit?

[Fotogirl_apc]

This was originally posted on APC forums on 1/17/2013

---

**Time to replace the unit?**

Have a ES550 and it recently started to click, often after three years of silence ~
Green light is on, no unusual equipment plugged in, location of unit hasn't moved for two years, no electrical work in the area.

iMac, 3 external drives & printer connected...

Any thoughts?

Thanks in advance for your comments.

TC

[BillP · Accepted solution]

This reply was originally posted by Angela on APC forums on 1/17/2013

---

hmm. clicking does not always mean its time to replace it. clicking usually tells me the UPS is transferring back and forth from battery to online operation. if it were me, what i would so is maybe test the UPS with a non critical load to verify operation and see if the clicking sounds similar there. so maybe remove your computer from the UPS power and use something like a lamp/clock radio where its easy to tell if the device is on and off. connect up the lamp or other device and remove the plug from the wall to see if the UPS supports the lamp. plug it back in to ensure the UPS comes back online.

do you have anything configured with this UPS within energy saver? it'd require the UPS data cable between your Mac and UPS data port. just curious.