Genesis woes

I recently bought what was advertized as a "new in the box" Genesis 2 off of eBay (from a reputable seller with over 300 positive and not a single negative feedback) just so that I'm not abusing my Nomad all the time. Anyways, while this system was advetized as "new" it was in reality mint but one of the best looking Genesis 2 units I have seen in a long long time. Definitely a well kept unit...or so I thought. About ninty percent of the time when I pop in a game and power it up, it freezes solid on the "Presented By Or Under License From Sega Enterprises Ltd" screen. I have tried to clean the contacts as best as I can and I am using games that I have previously bought brand new and are very clean. All of my games have worked fine for years in my Nomad but give me this trouble on this Genesis 2. Only after turning the thing on and off a zillion times or switching game carts sometimes can I get it to go. Once it finally does, it is rock solid.

So, is this merely a problem with the connector in the unit or is something electically wrong with this system? If there is an easy fix, please let me know. Otherwise I'm off to leave some very negative feedback...
Try to get a refund/replacement before leaving negative feedback though :
: If he has decent feedback he'll probably try to resolve your problem. Chances are he just didn't test it because it looked good.
Hi. Perhaps your unit is in perfect state. Try to use another power supply, like an universal adaptor or another genesis supply unit. Maybe your power supply have a trouble in the conector (broken cable that make contact sometimes....)and not give the power when you want. Try it, good luck!!!!!. Sorry for my poooooor english. I´m from Spain. Remember people Spain is in Europe............XDDDDDDDDDDDD
The cart port may be dirty, or the pins in the port may be forced wider than they should be, making poor connection. My oldest Genesis 2 (1992 vintage) has this problem. You could maybe try a pair of tweezers or a bobby pin or something to pry up the metal pins a bit. I haven't ever done this myself but if you're careful it won't hurt anything.