panasonic dvd home theater?

i had the inscription f61 on my panasonic home theater screen due to de result of adding an additional speakers which accidentally brought that inscription,want to know how I can fix it n what caused that.

my Panasonic home theater got de inscription f61 written on de screen due to de result of fixing additional speaker to de normal ones and the music accidentally stoped till date want to know what caused it n how to repair or fix it.