So I have an old iMac from 2009 and I decided to replace my thermal paste since it was overheating and now when i press the power button I hear the chime and a half second later it powers off. I triple checked that all the cables were in the correct place and they were. The ram was fine as was my ssd. What could I be doing wrong?
Earlier displays & monitors
There are four diagnostic LEDs on the MLB which may help, but more than likely something was damaged when you removed or reinstalled the MLB. Are you sure the heatsink was actually reinstalled properly? If it is not even, then the system may be overheating. Unfortunately I cannot provide a link to the description of these LEDs as they are on sites where the moderators will remove links to them. It is easy enough to search them out though, plus you may even locate the Apple service guide for your particular model iMac which will provide a troubleshooting flowchart & steps to attempt to narrow down the problem to one of the major components.
Some of the connectors are also very delicate & easily damaged (especially for the Display), so you may want to check them as well for possible damage.
There are four diagnostic LEDs on the MLB which may help, but more than likely something was damaged when you removed or reinstalled the MLB. Are you sure the heatsink was actually reinstalled properly? If it is not even, then the system may be overheating. Unfortunately I cannot provide a link to the description of these LEDs as they are on sites where the moderators will remove links to them. It is easy enough to search them out though, plus you may even locate the Apple service guide for your particular model iMac which will provide a troubleshooting flowchart & steps to attempt to narrow down the problem to one of the major components.
Some of the connectors are also very delicate & easily damaged (especially for the Display), so you may want to check them as well for possible damage.
So I found the issue. I accidentally broke the display ribbon cable. I have since replaced it and it works perfectly. Thanks to all who tried to help 😊
There are dozens of things you could have borked during your attempt to do that.
It's impossible to diagnose hardware and electronic issues by "remote control". Besides that, your Mac is obsolete and Apple will not work on it.
I am well aware that they wont repair it. That is why I did it myself.
How'd that work for you?
Good job! Thanks for following up.
Enjoy your revamped iMac.
Older iMac self repair problem
