You have a couple of options as I see it please try these steps might help you to fix your issue.
1) Disconnect the Battery & Adapter then press & hold the power button on Notebook for 30 seconds then turn on the unit and check if the Wireless light turns on.
2) Go to Device manager then uninstall the wireless drivers from Network Adapter and restart the unit and check if the light turns on.
3) Try doing a system restore to the date where unit was working fine.
4) Please update the Bios & Wireless driver from HP website.
5) Click start in search type Recovery Manager then click on it select Yes on User access control then select I need immediate help then select Driver & application recovery select the wireless driver and install it then restart the unit.
6) If you are comfortable reseating the wireless card which will be on the back panel off your unit you could try this steps as well.
If still you have the same issue then you need to call HP Technical support and get the part replaced.
Let us know how it goes!
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