So this morning I could hear TV1, TV2, TV1+1 & TV2+1 but there was no picture.  All other channels were operating correctly.  I tried re-tuning but still no luck.  All the TVNZ stations are all on the same channel 34.  Signal strength and quality were all good.  The really odd thing was this only on the Sony TV set, the Samsung and the Kron set top box were all displaying pictures normally.

Any suggestions?