iPod Touch 5th Gen. wifi problem after repair

Looking for some insight here...

I have an iPod touch 5th generation with isight rear camera 16GB. I have done many iPod touch repairs (what a pain!)

On this one everything was working fine, (wifi too) I took all the guts out of one case and put into another case (the old case and screen was really banged up)

After I did this, the "new" iPod will no longer connect or see wifi points unless we are right next to it. I immediately thought it was a broken antenna so I replaced it. But this did not resolve the issue. I then took all the guts and put it back into the old case, and it is still not connecting to wifi.

Any idea what could be going on here? I did a VERY careful repair and transfer.

BTW I'm doing the testing with all the guts kind of loose, meaning I haven't screwed anything back down (except for wifi antenna is still in place (and connected of course)