All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
There are three situations in working as a cable T.V. or modem fixer:
The first situation: If you know or are sure that the owner of such a device whether a television or computer is going to use it in what is forbidden, in such a case it is forbidden for you to work as such, even if he is going to use it sometimes in what is permissible as this is considered as helping in forbidden matters. Allaah says (which means): {(Help you one another in virtue, righteousness and piety but do not help one another in sin and transgression)}[5:2].
The second situation: If you know or are sure that the owner will use it only in what is permissible, then there is no harm on you to work as such.
The third situation: If it is an equal probability, or that you do not know for which purpose he is going to use it. In this case, you should act according to the use of the majority of the people there, if it is most likely that they use it in what is permissible only, then you can fix for them, otherwise [and this is the dominant case in the country that you have stated] (i.e. if they use it in forbidden matters) it is not permissible for you to fix for them.
Allaah knows best.