input: Household equipment (either yours or your neighbour's) can cause interference which often affects broadband speed. Things like TVs, alarms, fairy lights and set-top boxes are known to cause problems. [Cause] 
output: Electrical interference
options: B r o a d b a n d F a u l t s
options: T e l e p h o n e F a u l t s
options: W i r e l e s s
options: W r o n g l y s e t u p m i c r o f i l t e r s
options: B a d w e a t h e r
options: E l e c t r i c a l i n t e r f e r e n c e
options: Y o u r c o m p u t e r