I have a RCA cable modem connected directly to my computer via ethernet, Every 15-60 min my internet will cut off. The modem will stop its normal light blinking and will flash three lights simultaneously, it seems to be random when this happens and sometimes its out for a few min, and sometimes for 30 min +

I've contacted my ISP and when my modem is connected they tested it and I have full connectivity and they see no problem, the only option they have is to send a tech over, but I have no money for that right now, nor for a new modem. What could be causing this? Its completely random from what I see, I've reformatted, power cycled the modem countless times, reset the modem, yet randomly the internet will go out.

Please help me, I will try to answer any questions.

Well the only problem I see so far since it is not the problem of the ISP then I guess your modem is messed up and needs to be changed, in my point of view there is no solution on how to fix it, because even making reset to router or anything won't actually change its INTERNAL problem.

That helps...

Unfortunately I would give you a better solution if there was, but there isn't, the problem is coming from the modem. or what you can do is RENT a modem from the ISP as they may have a couple for renting and cheap.