[Equip] How often are cable modems the source of packet loss?

Been having packet loss & frequent T3 timeouts on my BCI connection w/cust. owned SB6141 for the past few days. Signals don't look bad, few codeword errors, problem happens over multiple computers each plugged directly into the modem, yada yada. I saw a Comcast bucket truck in the neighborhood recently with a guy working on what looked like an opened amp, and the problems started later that night. Before I try swapping the modem, then if that doesn't work blaming it on something outside my house, curious, how often do cable modems actually fail/cause errors? I've read that a large portion of cable modems sent back to manufacturers have nothing wrong with them... -- no place like ::1