A1278 820-3115-B tarts to boot then half way through just shuts off


New member
Working on a A1278 MBP with 820-3115-B board that will power up and start to boot. The display shows the normal Apple logo and progress bar then about half way through the progress bar the machine completely shuts off as if the battery was disconnected. Board reacts normally to an SMC reset. There is no indication of liquid damage. Can someone point me in the right direction ?


Staff member
I forgot to mention, start with external USB OSX through USB.
So you can discard HDD, or software issue.
I recently got one old iMac with same behavior, fixed by reinstalling OSX.