Loss of Dial Tone - sometimes faint - can FIOS cause this?

[Lesliemm]

I have a DSL line for phone and internet.  Late last week I noticed my dial tone was dropping to the point that it is now gone.  Sometimes when I disconnect for 5 minutes I can hear the dial tone faintly - or the recording telling to put my phone back on the hook.  So I know there is some signal coming through. 

I've set up for an appointment but wonder FIOS has recently been added to my building can that impact my landline? I know some neighbors lost service when it was being installed.