NFC problem

[Xg]

my xperia sola NFC not function.
I had updated latest LiveWare manager & Xperia SmartTag Apps, put & stick the xperia smart tag behind the phone for minutes, still not able to detect.
and i run the NFC Diag Test with below result (screenshoot), anyone know how to solve it? Xperia support don't  have any solution yet.

The phone just return from warranty repair (swap mainboard & done all stress test: as refer to Xperia Support service centre)

[XperienceL]

Same problem here dunno what to do. Bad past experience with Sony service centre.