Problem with internet (modem problem..)

Hello, recently my internet keeps shutting off and everytime I restart my modem, first three lights keep flashing and it gets stuck on those three lights. After like 10 mins, it fixes itself. Lately it has been happening too many times so I need some advice.

I have comcast broadband internet connection and I have their modem: RCA DCM 425

I wonder if I should call up comcast and just get a replacement or maybe there might be a permanent if not at least temp. fix until I can get a new modem

thanks again...

also I have a question... can a semi faulty or defective modem effect only the wireless portion of a router connected to the modem??

My internet situation is getting worse...ughh