Antenna contacts don't contact the way they used to.

After replacing the motherboard on my Nexus 7 2nd Gen, the Wi-Fi performance has severely deteriorated. On the Nexus 7 2nd Gen, there are four spring contacts visible between the motherboard and the back of the unit, as well as three contacts on the bottom of the motherboard between the mother and the Wi-Fi antenna.

There are several articles on the internet that talk about flexing and bending the contacts on the motherboard to reset and improve the performance of the various antennae in the unit. I've popped the back off this unit a half dozen times or so attempting to bend and improve the contact, but still I'm getting bad performance that is now where near as good as the Wi-Fi signals I got with the previous motherboard.

Has anybody had any success with other fixes to restore wi-fi performance on this tablet? I'm on Android 4.4.4 right now and planning to stay with that version until I'm assured that there is a version of Android 5 that won't brick my tablet like happened two weeks ago, necessitating the motherboard replacement in the first place.