WIFI Hardware Not Found After Sleep

Hi,

I have purchased an A1304 Mid 2009 MacBook Air and I am having trouble with the WIFI card.

It shows as No Hardware Found in the system tray and after searching online and eventually purchasing a new card (arrived and fitted today) It still shows the same message.

Once I reset the PRAM by holding down alt>cmd>p>r until the second boot up sound the WIFI works fine. It shows in the system preferences and all the details of the card show up in the system report.

However if I close the lid of my MacBook and reopen OR restart the machine I am presented with the same No WIFI Hardware Installed issue.

Could anyone please offer any assistance on this?

It is fully updated running OS X El Capitan 10.11

Many Thanks