Chosen Solution
@blinkoutatime so it was JUST one CPU pin which made the whole system not work/turning on? Do I understand that correctly? 😯 Because I have a similar problem changed the RAM, the CPU and the hard drive… I did everything really carefully and exactly according to instructions from iFixit and now my iMac isn’t turning on… 😩🙈 checked the power supply and the power-button cable but everything seems to be fine 🤷🏻♂️ … HEEELP 😥
@samkln - Reseating the CPU after removing to swap it out or just to clean the paste off the CPU and heatsink to apply fresh TIM can be difficult so one or more pins can get messed up if the chip is not seated properly. Apple makes the task quite hard as the tension springs are quite tight. Update (01/16/2023) @samkln - OK that list offers a clue! Sound like you did it all at once So now we don’t know for sure what is messed up. While it’s a pain I try to limit the amount of change to make diagnostics easier. So… the first thing here is popping out the CPU and yes, putting the i5 back in, in case you have a bad chip as well as check the socket pins with a good magnifier. I would also pull the blade SSD for now and I would setup a bootable external drive with what your system currently has (copy over the OS installer onto it as well) As far as overclocking sorry Mac’s don’t offer that, what the firmware is set to is what you have.
