Imac in my office behaves very strangely at times. Many times in case of power failure in spite of being powered via 1KV UPS, it gets switched off instantaneously and won't startup.
Then, if I put it on mains, it boots up fine and thereafter it boots up fine on UPS also.
I am unable to understand why I have to take it to mains if the UPS is new and fully charged.
You indicate that your UPS is new and fully charged. What is its kVA rating of the UPS, and is it sufficient to power your iMac and any peripherals that are attached? What brand/model UPS do you have. I have several UPS systems for my computers and I need to replace the lead-acid batteries in them every 4-5 years or they will not keep my computers running during a power outage. You have a new UPS, so you may want to put a note on it with the install date as a reminder so you know how old the batteries are and can be prepared to replace them when appropriate.
This article provides the approximate max/min power consumption for the various iMac models. Make sure that the specs for your UPS provide sufficient capacity (plus some overhead) to power your iMac at max load, even though most of the time your system will likely operate well below the max values.
The power supply may be failing. However it also may be caused by software. Please do the following:
Please navigate to the Mac App Store or navigate to www.Etrecheck.com and download the free version of EtreCheck. Once you have you downloaded the app and installed it, please run the report and save it. This report will help us get a good idea what has been installed on your system and help us be able to diagnose what may be wrong.
When you have your report, you can attach it when you reply to this message and we can then review it and help you determine what is needed to get your system running well again.
For instructions on how to download your EtreCheck report and attach it to your reply to this message please click https://discussions.apple.com/docs/DOC-250000211
IMac strange power issue
