Chosen Solution
I have beloved mac book pro mid-2012, that is not turning on. It has had a screen replaced 4 years ago, and been upgrade with an SSD and new RAM approximately 2-3 years ago, and a new battery, almost 1 year ago, by myself. It has been having some issues charging on and off for the last few years, which I have put down to charging cables, or dirty charging ports but this time it didn’t seem like a problem with the cable. Recently the computer had been shutting itself off randomly when I moved a little bit jerkily, and then wouldn’t charge. But if I removed the back and unplugged the battery for a minute and then reassembled it would then charge and turn on. On this occasion, I moved the computer jerkily, and it turned itself off. The laptop turned on, but it wouldn’t charge, and the cable charging indicator was off. After I finished using it I turned it off as it was on approx. 50% battery and I wanted to be able to come back to sort it out. However, the next day when my partner came to use my laptop it didn’t turn on, and the cable charging indicator was completely off (not orange/green) and one of the LED battery indicators was lit but the third from the bottom and none others. My partner tried the removed the battery trick but to no avail. We then tried a myriad of button combination presses to get the computer to turn on. Nothing happened, nil sound of fans turning or anything at all. Just nothingness. I also examined and checked out the battery indicator LED button to check if it was damaged (or something ??). We concluded it must be a problem with the old charging port and I bought a replacement from ifixit. While it was waiting for to be replaced the LED light has remained lit and not gone off at all. Today I replaced the charging port. The charging cable LED when plugged in is green. The battery LED indicator third from the bottom is still lit and only that one. And the computer still doesn’t turn on, or even ignite the screen. I have googled extensively and haven’t seen anyone else with this issue. Could one of you kindhearted and computer minded geniuses please help me? I don’t want a new mac I love this one. Thanks for reading peoples of ifixit :)
This sounds like the battery checker board has failed and this could effect your systems ability to run. Here’s the needed part Unibody MacBook Pro 15" Battery Indicator Board,Apple P/N 922-9033
