Boot up issues after logic board swap
I picked up a used mid 2012 non retina MBP with the I5 and 4GB of ram. I bought a certified used logic board 820-3115-B and new ram for it.
I completed the swap, cleaning, new thermal paste ect and attempted to turn it on. Completely dead. I connected it to wall power and the green light on the plug lit up as well as the green battery indicators on the side. I open the lid and there was nothing from the power button. Closed the lid and heard the mechanical noise from the cd player centering itself. Opened the lid again and it eventually booted up but the keyboard was unresponsive.
Shutdown and checked all the connectors. the keyboard cable was not seated entirely. reseated the cable and tried again.
The keyboard backlight comes on but it won’t boot anymore. Also, when the lid is open the “sleep mode” light on the front slowly flashes and goes solid when I close the lid.
Any Ideas?
Is this a good question?
6 
1 
What is your drive a HDD or SSD? And what was the MacOS your system had on it before you swapped out the logic board?
by Dan
It has the original 500 GB HDD and I believe it's running OS X 10.7.3 "Lion"
by James Sargent
I swapped the old I5 logic board back in and everything works fine. Put the "new" board back in and have the following issues.
Laptop closed white power light is constantly ON.
Laptop open power light slowly flashes and the keyboard back light is on but there is no boot up.
by James Sargent
Sounds like you got a bad part
by Dan