Location [Q] WiFi greyed...all application running except Google Play Store

I am having Micromax Canvas Juice A77 with original JB 4.2.2 onboard (not rooted).

Since 3-4 days my wifi is behaving strangely.......whenever connected...it immediately turns to grey but I am able to browse or use all application except Google apps like play store...
I tried to try following tips/directions posted in the forum but none it worked for me.

1. clear cache of all google apps.
2. clear wifi and re-connect
3. put phone on Flight mode for 1-5 mins and turn to normal profile
4. deleted/uninstalled all apps from unknown source (downloaded from other places than play store)

One thing I noticed that when I logged in to my google play account and tried to see devices linked, it showed that NO DEVICE IS LINKED so I even tried to re-log in to the linked google account from device and computer but still my linked device is not reflected in accounts !

Tried to set location sharing on even with GPS but still problem is same...grey wifi with no support to play store which says 'No connection Retry'

Please help me out...