Chosen Solution
So, I tried to replace the RAM, hard drive, and CPU in my 2012 2544, and the only thing I haven’t tried swapping back into the thing is the original RAM, only because I know the sticks work, as I tested them in my laptop. On boot, the screen does nothing, and the fan just blasts air. Anyone have any idea what I should troubleshoot first? The second LED on the motherboard does not come on upon powering it up. I have a feeling this means my power supply is dead, but I want to make sure nonetheless. Update (08/23/2021)
The plastic on the left side is messed up. Should I try and shave it down?
This sounds like an improperly seated CPU chip! Time to go back in and take the CPU off and inspect the socket pins as you may have damaged a few. I often find the spring tension is hard to deal with, often failing to get the CPU to seat properly and what you are seeing with the diagnostic LED’s will react this way when you have shorted the ground pins. Also review your TIM application. Make sure the TIM is strictly on the lid not having gotten on the the carrier and the SMD devices on it. You’ll need to carefully! Clean it off making sure you fully remove the TIM (and clearly use less) The reason the fan is racing is the SMC logic is working (which also supports the power supply is fine). Here SMC is not seeing the sensors properly and will push the fan to the max and lower the CPU’s clocking to prevent you from damaging your system (CPU).
