Chosen Solution
Hello all, I have had my iMac, from new, since early 2015 and have never had this problem until recently. The problem is as follows: I have always shut my iMac down completely then switched off the mains supply to the computer, this has never been an issue. However, of late when I come to switch the iMac on by first switching on the mains power, the imac will switch itself on without the power button being pushed. Also, If, on occasion it does not switch it’s self on (about 1 in 10 times) the start up tone does not sound until 20 -30 seconds after the power button is pushed. Then it will start the boot up process. As I say I have had no issues at all with this computer until the last 2 - 3 weeks. I have done all the resets recommend and completely clean install of the latest version of Big Sur, None of this as made any difference. The Mac spec is: iMac (Retina 5K, 27-inch, Late 2014) 4 GHz Quad-Core Intel Core i7 32 GB 1600 MHz DDR3 AMD Radeon R9 M295X 4 GB Thanks in advance for any advice offered. Regards David
Ah! You’ve run down the NVRAM battery! The iMac requires a vampire trickle from the power line otherwise its strictly the coin battery and as the settings are getting lost now the system will react this way. Apple of course placed the battery in the hardest place to get to the backside of the logic board so you need to fully remove it to get to it! (bad design choice)
So this is a big job needlessly! If you’ve never opened an iMac I would let a good mac repair person or Apple deal with it.
