MacBook not turning on. No charging light on MagSafe.

:

• Macbook Air (13", A1466) not powering up
• No charging light on MagSafe
• No sounds, not even fan
• Screen will occasionally come on displaying charging symbol or low power symbol

• SMC reset
• Disconnecting and reconnecting battery
• Different charger (non-official but working)
• Cleaning charging port

Okay, so firstly this is not my MacBook Air and nor do I know much about them, so please keep things simple. This is my friends device, he said it was being used as normal and then it suddenly switched off and never powered up again - the battery was apparently at 40% at the time.

I have tried all the above fixes with no success so far. Upon trying a new charger the charging light initially turned orange before going off again, this makes me think that there is some kind of charging issue. Also the screen occasionally shows that the device is charging before quickly going off again.

Is the issue the charging port, the battery or perhaps something else. Any help and direction would be kindly appreciated as I'm afraid I have little experience working with Macs.

Marty