Just a heads up,
not sure how good you are with a screwdriver
But u can pick up a broken NES with those things for about 20 bucks on Craigslist,
Then go on amazon and buy a new cartridge reader for about 7 bucks shipped,
And install it. Only takes about 10 minutes.
I may be picking one up to fix soon if you are still looking I'll pm you a price for it fixed.