[Q] Sph-L720 - No mobile data ... Cant activate. topic

So here I am...that guy. I bought a Sph-L720 and I didnt check until It was too late. I think the previous owner downgraded the modem. It was running a stock rooted rom when I bought it Mk2 I believe but am not sure. I have since installed a complete mk2 stock firmware, modem, rom all inclusive which was downloaded from this forum. Anyhow any help would be appreciated in getting this thing up and running. Shows 3 bars of service.... just no data. Has a sprint sim card installed. Thanks ... - Dave(that guy)