Chosen Solution

Okay so I just did a logic board replacement. I installed the 2012 a1286 logic board in my 2010 mbp.(it fits) the problem is that when I start it up, it starts to boot properly(apple logo, progress bar), then suddenly shuts down during the boot. already tried booting into verbose, but it goes fine for a while then turns off too quickly for me to see anything. A thing that I noticed was that it turns off after variable times, like 1 time it went for about 15-20 secs but the next it turned off after 1sec. also tried booting from usb but that didn’t work too(same problem) Any solution?? UPDATE: ok so I used a cooling pad and the boot went on for longer! so could this be thermal related? I did replace the heatsink without thermal paste. also, some of the screws of the heatsink weren’t aligned with the holes so I ditched those. UPDATE 2: I used thermal paste and fixed the heat sink properly on to the board. It still didn’t boot. Then I left it and went to sleep. Tri ed to boot it again and lo and behold! It started up! Soon afterwards though, the fans spooled up and again it just turned off. Haven’t been able to make it boot up since. Update 2.5: after trying to boot it up countless times, it finally boot ed up to desktop again. i left it running idly. after about 2-3 minutes, a kernel panic appeared on the screen and 15 secs after that the same sudden shut down occurred. Update 3: so i created the el capitan usb as Dan and Dee suggested below. It went through the boot fine. Started the installation which progressed in the first 2 mins, then a kernel panic appeared. This time, i caught the culprit: appleintelcpupowermanagement. Anyway, i then removed the back cover ofthelaptop, placed it on the fan-cooling stand, and placed an ice pack beneath it. And…… it worked!! the installation took 30 mins. right now I’m posting this from this device and so far its working. It starts to lag when i put high load but otherwise its working fine!!. i also installed stats menu. after monitoring it for some time, i saw that on idle, the cpu temp stays around 70℃, and when using safari(like right now) its 90. it does reach 100 or 105 for a sec then falls back. Other than that the airflow is 40. So can you decipher the actual problem and the solution? heres a screenshot while using safari:

BTW my area’s average temperature is 35 - 37 ℃.

Sounds like your HD or the HD’s SATA cable is having problems. Do you have an external bootable drive (or CD/DVD) to try booting up under? If you do give that a try.

From the symbols, most probably the system files are corrupted. If possible, boot from an external operating system(if that works, that means the OS on the internal drive-or the drive itself is definitely faulty) and backup your data. If the disk utility says “D.U. can’t repair the disk”, doesn’t always mean the drive is faulty. Try to install fresh OS on your internal drive and see if it works.

I’d ask you to try what Dan said. Use a bootable drive with El capitan os and get to disk utility. See if you can get to your hard drive. If it’s not repairable then format it. If you’re unable format try another hard drive and install osx. I have had a number of Macbooks with similar issues. Ps if it’s booting half way then your sata cable should be fine but hard drive damaged. Hope this helps.