I underline oferlaor's statement!
I have a Sony KV-28FD1E and had the same problem. The picture slanted down to the left side. This was manageable in the setup menu.
But, I was faced with another problem! The picture was not centered correctly and that differently for each picture mode (4:3, 16:9, etc.). I was lucky enough to have the technical plans with all the setting codes. See there, you have a hidden menu that allows you to adjust deflection control. On my set I can enter that menu by pressing "PROG +" and "PROG -" at the same time while the tv is in standby.
CAUTION: If you don't know what your doing you can mess things up badly.
I suggest you call a good technician as oferlaor stated.