Wifi comes and goes

I am repairing an ipod touch 4th gen 32gb. The wifi was showing "off". I tried installing a new antenna and it still was greyed out. I put back the old antenna, and went to have dinner. When I returned, the wifi was showing up, but it wouldn't detect my network unless I went right up to my router. I reinstalled the new antenna and got decent signal from around the house. I closed up the ipod, and now the wifi is showing "off" again. I've restored several times, but to no avail.

Any ideas?