Why I don't get horizontally-polarized TVs in the satellite from time to time?
The 14/18V electrically controlled polarizer is integrated within the LNC and runs thru the coax cable. 

Issues may exist with DC supply voltage, polarotor, the co-rotor, the skew alignment, the channel programming or the LNC or very advanced microwave propagation issues with solar angle.

C-band Channel Polarity map.

Map for others