I have managed to borrow a friends magsafe board and it's not that. Easy and reseda lay cheap to try.
Since its been subject to liquid damage I instantly shut it down removed all power and stripped the machine completely. Cleaned all the liquid I could find with an achohol solution and left it to dry for 5 days.
Put it back together and everything works off battery fine. As soon as I connect the magsafe connector to charge the machine the display switches off and there is no charging led lit.
As soon as I remove the magsafe connector the screen comes back on...
I suppose I will have to take it into apple and tell them what happened and see what they say.
Thanks once again you are very kind to offer to get me the part
Hi I have checked all the cables from and two the magsafe board.
The main flat cable that runs from the magsafe Board to the logic board looks like it has a pin missing which might be the reason why it doesn't charge or it switches off when I connect power from the mains adaptor
If anyone can look at this picture and compare a working MacBook Air 2012 I would be very grateful
I have several Mid 2012 Magsafe i/o boards and cables.
None of them have a missing pin like yours pictured.
If the moisture sensor on the underside of the flat cable still white or is it now red?
Sorry about the poor pictures, low light and cell phone camera
To be on the safe side it may be best to purchase both the cable and board.
Many times on ebay that is the most cost effective way, then you are covered.
If it turns out you don't need the board, you will always be able to sell it.
If your cable does not have that sensor within my first picture
Someones been inside that air at some point. They are just stick on sticky back stickers.
You will find them in several locations of the logic board, and on the underside of the battery. The battery alone has about four or five of them near/on each cell.
I suppose it is possible that Apple omits them in the units sold in your country
Be sure to search ebay under several terms such as "mid 2012 air i/o board" & "mid 2012 air magsafe" "mid 2012 air magsafe cable" Then be sure to purchase the correct one for the 13" not 11"
Like = http://www.ebay.com/itm/111190994533?ru but not necessarily from china