Are you adjusting it in service mode? Sounds like "S-distortion" to me(there's bold text about this in service manual). The trick is to adjust it in 5x7 mode(press 0 five times to go into this mode) to fix it, then fine tune in 7x13 mode. Read the service manual on "digital covergence adjustment" carefully.
I don't think you need new chips. Start from service mode adjustment.
I don't think you need new chips. Start from service mode adjustment.