View Full Version : iMac blinking diagnostic LED.

03-10-2019, 02:15 PM

I have an iMac 27" (late 2012) 2.9GHz with 8GB RAM and 1TB HDD.

One day the monitor would just grey out and restart and it did that for a while until recently it just powered down on its own and has remained like that for the last 4 months.

There are two DDR3 4GB RAM sticks which I have moved around but to no avail.

The Apple support thought it was the PSU but they tested a new working one and no change. They thought is was the motherboard so they replaced and still no change.

There is one blinking LED on the motherboard when power is connected but when I press the power button the blinking just speeds up for as long as the power switch is pressed. Letting go would get it back to its original blinking rate.

I have absolutely no idea how I can fix this. I have stuff on the HDD that I would like to get back to.

Hope some one can help me.


03-10-2019, 03:54 PM
Sounds like you need a new power supply. Look here: https://www.ifixit.com/Answers/View/408712/Apple+STUMPED+-+iMac+shuts+off+randomly,+daily+to+multiple+times-hour

03-11-2019, 12:55 PM
One thing of note, a hard drive is a hard drive is a hard drive. You can always pull the drive and install in an external case.