SB4200 Cable Modem Issue

[Tycoonbrad]

Motorola SB4200 Cable Modem

I'm having issues with my cable modem. My cable provider told me I had old lines so I replaced all the coax with quad shielding RG-6 cable in the house. I had my cable provider remov all the old unused lines from the box. I now have two cable lines and one cable modem line.

Here's where I think the problem lies...the Downstream Power Levels.
Signal To Noise Ratio 29 dB
Power Level -19.0 dBmV

Yes, that's -19 dBmV. It never goes below -12 dBmV. My SNR usually ranges from 21 to 30 dB. I get drop outs frequently.

What does a high power level usually mean? Does it mean I don't have a ground block?