Dsl internet connection unstable?

[nlucky]

My modem's dsl light was blinking so i had no internet connection and i had a technician come in. When he came in, the modem was working, so he said if it continues to D.C buy a new modem. the internet was working fine until night, when it crashed again so i went out to buy a new modem, Motorola. I changed all the filters and cable and it was working great all day. However the next day the DSL light was blinking again, so no connection. so i called for a technician to come tomorrow, and now its working again. Anyone had this problem?

* Phone has static, sometimes solid DSL light when i call the DSL company
* Technician came and did something to make connection more stable
people have said it might be filters since it has static but i bought brand new modem with filters
and another weird thing is, when i use the phone, the internet works.... is that evidence of something else that is wrong? like phone line? and how do i check?