Update driver first and restart OS. 

If the issue remain the same,  reseat the Wi-fi card and antenna .

If the ping value remain unstable, high, or no connection, then swap with a known good wi-fi card for testing.

If the issue remain the same, the it is most like the wi-fi card is defected.

ping command
ping -n 100 -i  255
-i : It sets the Time to Live (TTL) value, the maximum of which is 255.