2010 iMac doesn't turn on after unplugging

[tximacusr]

I have a 2010 iMac 21.5, i5, 3.6 GHz, 4G, 1T.

When new and the first yr or two, before I would go to bed, I would turn off the power surge protector where the iMac and other hardware was connected. After a few yrs I realized that it would take longer for the iMac to "power up."

Now, I leave it connected to the power surge protector and on so I won't have to worry about this. I disconnected the iMac this past weekend to clean the room and connected it back on Monday, but it won't turn on now.

Does it have a "power pack" inside that needs to be "charged" before it can be turned on? What exactly is going on here? Last time it did this it took days before I could turn it on again. Assistance is requested. Thanks!

 

[asriznet]

I have a 2010 iMac 21.5, i5, 3.6 GHz, 4G, 1T.

When new and the first yr or two, before I would go to bed, I would turn off the power surge protector where the iMac and other hardware was connected. After a few yrs I realized that it would take longer for the iMac to "power up."

Now, I leave it connected to the power surge protector and on so I won't have to worry about this. I disconnected the iMac this past weekend to clean the room and connected it back on Monday, but it won't turn on now.

Does it have a "power pack" inside that needs to be "charged" before it can be turned on? What exactly is going on here? Last time it did this it took days before I could turn it on again. Assistance is requested. Thanks!

an SMC Reset usually fixes power related issues unless there's a hardware fault, you will need to bring in to a service center for them to check.

Good luck!

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve
Shut down the computer.
Unplug the computer's power cord.
Wait fifteen seconds.
Attach the computer's power cord.
Wait five seconds, then press the power button to turn on the computer.

 

[macthefork]

It does have a PRAM battery that holds some settings when power is disconnected. If you disconnected it for years every night, it's a good possibility that this battery needs to be replaced. You can look up your exact model to see which battery it is. And yes, a failed battery can cause some strange starting problems.

Unfortunately, the iMac screen has to be removed to replace this battery, since it's usually located on the Logic board.