sanyo ce21mt3-d TV?

I had the same problem, as it is not very intuitive from the remote. If you still need to know, read on...
You need to press the F... button on the remote repeatedly until PRESET NO/YES appears. Once you select YES, then you need to press the F... button again to cycle through AUTO Tuning, Semi Auto tuning and manual tuning. Answer came from searching for the manual on the SANYO web site, once found, the tuning instruction is on p.10.

smia
November 2010