MacBook Air 2013 suddenly dead, declared dead by Authorised Repairer, then suddenly ALIVE!

Over 3 weeks ago I was using my Macbook Air (mid 2013 model) and as usual closed the lid when finished and walked away. A few hours later I opened it only to find was was completely dead. Black screen and no signs of life.

After a small panic I put it on the charger hoping the battery has just somehow miraculously gone dead (even though it had been above 80%). The orange light came on and eventually turned green. When pressing the power button nothing seemed to happen. I tried it multiple times over the hours and nothing happened. I eventually put my ear to the keyboard to listen and sure enough I could hear some signs of life but no boot.

We were away for the weekend so I left it on the charger and when home late the next day tried it again. Same result. Nothing.

So I took it to our local Apple Authorised Repairer. It unfortunately took them 3 weeks to even look at my computer and when they did they reported that they found a minuscule pin to the display was bent and that my whole display would need to be repaired.

I questioned a little further and asked if they could hook it up to a monitor so I could at least get all of my stuff of it. He said that wouldn't work as they had already tried it.Confused I asked if the main board was dead and he said that he could see that fans working but yes, the main board must be dead as well.

They advised that the repair would be over $1700 and that instead they could sell me a new MacBook air and try and recover my data onto it. That is was DEAD.

I was shattered!! This was my work computer and I had some serious work I wanted to get off it. Unsure what to do I asked them to put it back together and after paying the $120 bill I took my baby home.

My tech savvy brother in law offered to have a look at it for me and after 4 weeks of no computer he took it home to check it out. He got as far as opening it and pressed the power button when PRESTO!! It was ALIVE!!! I'd tried it myself several times since getting it home with no result.

As thrilled as I am that my baby is back to life, can someone please explain what on earth happened!!! Our local repairer told me it was DEAD.

I could have thrown it away for absolutely no reason based solely on their proffesional advice (which I had paid a pretty penny for mind you!).

When I mentioned it to them, all they could say was it must have been a battery fault.

Is it just me, or should they have known? They are Authorised Apple Repairers.