11" mid 2010 MacBook Air stops charging @499 cycles

My mid 2010 11" MacBook Air does not charge anymore (MagSafe 1). The adapter shows no light (red or green) so:

- I got a new adapter (original). no effect

- I have had the internal connector replaced (3rd party). no effect

Basically I will be given back the macbook with no cure. Any similar experience and possible a solution?

PS just before the battery drained completely, the system info screen read that the battery had 499 cycles. A coincidence?