Dell vostro 3550 no ethernet available at all/mysterious

dear All

I have a problem with ethernet cable being not recognized by the computer. its 9 years old laptop with windows 7 64 upgraded very recently to win 10, but the system seems to make no difference.

Few years ago i replaced the wireless N-1030 card for dual band AC7260. i noticed then under device manager ac 7260 plus 8 different WAN miniports listed. no ethernet at all.

recently, I've uninstalled all network drivers + the software of 7260 separately but they come back in the above form, after any reboot. plugging ethernet cable doesent help, it s not being recognized, nor I see any proposed LAN connections under network adapter options.

The audio/ethernet/usb board inside looks OK and all other audio/usb ports on it are working OK.

the bios a11 shows NIC (I believe this is for ethernet) adapter enabled. Btw dell support said to upgrade bios but my ststem then crashes so I abandoned it.

Has anyone any idea what my problem may be and how to make my dell see the ethernet cable plugged in?

Cheers.

Chris.