the 2012 and 2013 only difference is the connector of the isight camera..the 2013 and 2014 is the same :)

Boot the Mac without the battery connected and see if works normally..did you check if there is not issues with the battery connector? If you can log check on system report > Power what the battery said if is connected? did you already glue the battery on the top case?

I will suggest you to copy the important files and reinstall the MacOS from the recovery partition.What brand of SSD did you purchase.

Could be the display cable.

I think that If someone did replace your logic board you need to check with him first to see what’s the problem because if you try to make your stuff and was the logic board installation there is not way to prove that was a bad logic board installation or the logic board have fail. Regards

Como estas, lo que debes es buscar una pantalla que este funcional y terminar tu reparación ya que si rompiste los cables que son (dos) debes de recordar que no hay comunicación del home buttom y el logic board.Como vas a tener que cambiar la pantalla tienes que tener muchooooo cuidad con el home button porque si lo rompes el flex tundras que llevarlo a Apple porque no servirá. Buscate una pantalla y a reparar esa parte…si necesitas info de como quitar el home y la cámara con gusto te puedo ayudar..saludos!

Well I think you should take a closer look to see if there was no liquid presence in that keyboard because normally when key fails is that and because you remove the trackpad this will not cause the issue because you did disconnect the keyboard cable to remove the trackpad I believe…I think you can use a wired keyboard and try all the keys and if works you will need to replace the keyboard. Regards

If this is cause by temperature I believe you could have some hardware issue (component) issue.I think you can try another flash but you will need to remove the power button cable completely to change the flashlight.

I think the certification will give you good information about costumer service and ESD SAFETY that we know is very important for us for the safe of the devices.But I think this certifications will not prepare you in 5 days to resolve the issues of the day and day.I did take the test for ACMT and ACiT and was a little bit hard because all the information that you need to read and remember…did pass and get my certifications but without AST2 is like know how to drive a car but don’t have a car and this can only be posible to use if you work for Apple or you are a AASP if not you can’t use the diagnostic tool.But is good because clients will be more confident to bring the devices. I will recommend this to anyone that loves to work with the Macs,that likes to talk to the clients and explain stuff to them and of course to understand more how the ESD SAFETY works and how you can use this for your day.I think is a another thing that we can learn and of course is good to show your title and knowledge to the...

If you see a question mark folder is that the Mac don’t find the MacOS.You can try this : Power off the Mac than power on and hold the keys Comand + R and the Mac will boot in to the recovery partition.From there you can go to disk utility and run a disk utility in that SSD to check for errors.If you don’t find any errors from that partition you can try to reinstall the MacOS and see if that can fix the problem. Another option is that you remove the ssd from the Mac put on a external enclosure en boot from the external enclosure using command (option key) and see if you can see the drive or if you can boot.I have seen MacBook Air ssd damage ramdonly so I suggest you to check if that drive is good first :)