internet dropping

My internet kept dropping and after rebooting the modem and router multiple times, with no improvements,Cox sent out  a technician and he removed an old filter at the backyard pedestal. Of course everything checked ok.  Next day, same thing, random drop-outs.

Then another set of technicians came out and replaced a few connections etc. and everything checked ok. Next day, same thing, random drop-outs. Then Cox sent out another technician that replaced the modem, ran new RG11 from the backyard pedestal to the house interface and new RG6 from the interface directly to the modem!!  He did an excellent job and everything seemed to be ok until a few days later when it dropped out again. I tried rebooting the modem to no avail.  I found that by removing and reconnecting the coax at the modem it came back on!  It has now happened about 4 more times and removing and reconnecting the coax at the modem got me back up and running . Coincidence? 

 NOTE:  1.The technicians checked other users that were fed from our pedestal and no reports of problems.

              2. When I say dropped out or drop-outs, I mean no "..online.." light on the modem and my computer shows .."no internet connection".

Any info or insight or recommendations or solutions will be appreciated!!

Thanks,

Capron